¹ See especially G. Striker, ‘Κριτήριον τῆς ἀληθείας’, Nachrichten der Akademie der Wissenschaften in Göttingen 2 (1974), 47–110; ead., ‘The problem of the criterion’, in ead. (ed.), Essays on Hellenistic Epistemology and Ethics (New York, 1996), 150–65; E. Spinelli, ‘Epistemologie ellenistiche: il problema del criterio’, in id. (ed.), Storia della filosofia antica (Rome, 1996), 169–96.

² Diog. Laert. 10.31 (= fr. 35 Usener) ἐν τοίνυν τῷ Κανόνι λέγων ἐστὶν ὁ Ἐπίκουρος κριτήρια τῆς ἀληθείας εἶναι τὰς αἰσθήσεις καὶ προλήψεις καὶ τὰ πάθη. See also Cic. Acad. Pr. 142 (= fr. 245 Usener). On Epicurean perception, see C.C.W. Taylor, ‘All perceptions are true’, in M. Schofield et al. (edd.), Doubt and Dogmatism: Studies in Hellenistic Epistemology (Oxford, 1980), 105–24; S. Everson, ‘Epicurus on the truth of the senses’, in id. (ed.), Epistemology (Cambridge, 1990), 161–83; Hahmann, A., ‘Epikur über den Gegenstand der Wahrnehmung’, AGPh 97 (2015), 271–307CrossRefGoogle Scholar; K. Vogt, ‘All sense-perceptions are true: Epicurean responses to skepticism and relativism’, in J. Lezra and L. Blake (edd.), Lucretius and Modernity: Epicurean Encounters Across Time and Disciplines (New York, 2016), 145–59; on preconceptions, see Long, A.A., ‘Aisthesis, prolepsis, and linguistic theory in Epicurus’, BICS 18 (1971), 114–33Google Scholar; A. Manuwald, Die Prolepsislehre Epikurs (Bonn, 1972); F. Jürss, ‘Epikur und das Problem des Begriffs (Prolepse)’, Philologus 121 (1978), 211–25; V. Goldschmidt, ‘Remarques sur l'origine épicurienne de la “prénotion”’, in J. Brunschwig (ed.), Les Stoïciens et leur logique (Paris, 1978), 155–69; Glidden, D., ‘Epicurean prolēpsis’, OSAPh 3 (1985), 175–218Google Scholar; Morel, P.M., ‘Method and evidence on Epicurean preconception’, Proceedings of the Boston Area Colloquium in Ancient Philosophy 23 (2008), 25–48Google Scholar; Konstan, D., ‘Commentary on Morel’, Proceedings of the Boston Area Colloquium in Ancient Philosophy 23 (2008), 49–55Google Scholar; Milos, A.G., ‘Epicurus on the origin and formation of preconceptions’, Croatian Journal of Philosophy 12 (2012), 239–56Google Scholar; Tsouna, V., ‘Epicurean preconceptions’, Phronesis 61 (2016), 160–221CrossRefGoogle Scholar. On feelings, see N. DeWitt, Epicurus and his Philosophy (Minneapolis, 1954), 150–4; D. Konstan, ‘Epicurean “passions” and the good life’, in B. Reis (ed.), The Virtuous Life in Greek Ethics (Cambridge, 2006), 194–205; Verde, F., ‘I pathe di Epicuro tra epistemologia ed etica’, Elenchos 39 (2018), 205–30CrossRefGoogle Scholar. On Epicurean epistemology more generally, see E. Asmis, Epicurus’ Scientific Method (Ithaca and London, 1984); F. Jürss, Die epikureische Erkenntnistheorie (Berlin, 1991).

³ ‘Indeed the person who does not know how things that appear to the mind will be judged thinks that inferences from signs should be constructed if they are verified by observation and do not conflict with all the things that are called criteria of the unperceived, with perceptions, preconceptions, φανταστικαὶ ἐπιβολαί τῆς διανοίας, and feelings’ (ὁ δέ γε ἀπορῶν πῶς [κριθήσε]ται [ἡ] τῆς διανοίας φαν[τασία συ]νθ[έ]τον τὰς σημει[ώσεις οἴ]εται, ἐὰν ἐπιμαρτυ[ρῆται διὰ τῆ]ς ὄψεως μήτε τοῖς πᾶ[σιν, ἅ κριτ]ήρια λέγεται τῶν ἀδή[λων κα]τὰ τὰς αἰσθήσεις καὶ [προλήψεις κ]αὶ τὰς [φα]νταστικὰς [ἐπιβολὰς τῆς διανοί]ας καὶ τ[ὰ πάθη, ἀντιπίπτηι]); Phld. Sign. fr. 1.6–15 De Lacy and De Lacy, their translation.

⁴ The most important discussions are the following: T. Tohte, Epikurs Kriterien der Wahrheit (Clausthal, 1874), 20–4; R. Philippson, De Philodemi libro qui est: peri sēmeiōn kai sēmeiōseōn et Epicureorum doctrina logica (Berlin, 1881), 11–19; C. Giussani, Studi lucreziani (Turin, 1896), 171–82; F. Sandgathe, Die Wahrheit der Kriterien Epikurs (Berlin, 1909), 3–25; C. Bailey, The Greek Atomists and Epicurus: A Study (New York, 1926), 559–79; K. Kleve, Gnosis Theon: Die Lehre von der natürlichen Gotteserkenntnis in der epikureischen Theologie (Oslo, 1963), 110–19; Asmis (n. 2), 86–91, 124–6; Jürss (n. 2 [1991]), 75–83; Tsouna (n. 2), 186–93, 213–15; J. Muñoz Morcillo, ‘El Κανών de Epicuro en la Epístola a Heródoto’, CFC(G) 28 (2018), 141–57.

⁵ See also Asmis (n. 2), 105–6.

⁶ Ep. Hdt. 35, 36, 38, 50, 51 (twice), 62, 69, 70 and 83.

⁷ The fragmentary Herculanean papyri of Epicurus’ On Nature are often heavily dependent on additions by contemporary editors. Past editors have seen more references to ἐπιβολή in the text than more recent ones. While Books 25 and 28 (= P.Herc. 1191 and 1479) may contain references to the term, the received text is so fragmentary that the passages in question do not help to elucidate what ἐπιβολαί are. By contrast, On Nature Book 34 (= P.Herc. 1431, col. XI.3 Leone) contains a reference to ἐπιβολή that helps characterize ἐπιβολαί further and so will be discussed in more detail below.

⁸ For the Greek text of the Letter to Herodotus (and the Principal Doctrines), see G. Arrighetti (ed.), Epicuro: Opere (Turin, 1973²). The English translations follow those in B. Inwood and L.P. Gerson (edd.), Hellenistic Philosophy: Introductory Readings (Indianapolis and Cambridge, 1997²), but are sometimes slightly modified.

⁹ Sedley, D., ‘Epicurus, On Nature XXVIII’, CErc 3 (1973), 5–83Google Scholar, at 23–4.

¹⁰ Giussani (n. 4), 171; Sandgathe (n. 4), 17–18; Bailey (n. 4), 563; J. Annas, Hellenistic Philosophy of Mind (Berkeley, 1992), 165; F. Verde (ed.), Epicuro: Epistola a Erodoto (Rome, 2010), 135.

¹¹ More on this ‘active’ component below.

¹² Tohte (n. 4), 20–4; Asmis (n. 2), 88–91; Verde (n. 10), 72–3.

¹³ On mental images and perception, see especially Lucr. 4.722–822 and 5.1161–93, as well as Diog. Oen. fr. 9 Smith and SV 24 and Diog. Laert. 10.32. On dreams, see Tsouna, V., ‘Epicurean dreams’, Elenchos 39 (2018), 231–56CrossRefGoogle Scholar (with further references to older literature).

¹⁴ The textual conjecture is based on a scholium on Ep. Hdt. 50 that reads: ‘According to a certain motion in ourselves which is linked to the presentation-producing application, but is distinct, according to which falsehood occurs’ (κατά τινα κίνησιν ἐν ἡμῖν αὐτοῖς συνημμένην τῇ φανταστικῇ ἐπιβολῇ, διάληψιν δὲ ἔχουσαν, καθ᾽ ἣν τὸ ψεῦδος γίνεται).

¹⁵ C. Diano, Scritti Epicurei (Florence, 1974), 157–8.

¹⁶ D. Furley, Two Studies in the Greek Atomists (Princeton, 1967), 206–8.

¹⁷ J. Rist, Epicurus: An Introduction (Cambridge, 1972), 33–4.

¹⁸ A notable difference may be that mental perceptions of a centaur could be based on one image, while sense perceptions are based on a stream of images: Philippson, R., ‘Zur epikureischen Götterlehre’, Hermes 51 (1916), 568–608Google Scholar, at 569–70. However, it is unclear how this difference ought to influence the judgements of perceivers.

¹⁹ Diog. Laert. 10.32. See also Plut. Adv. Col. 1123A–C; Sext. Emp. Math. 8.63.

²⁰ Asmis (n. 2), 90. See also the discussion in Verde (n. 10), 138–40.

²¹ See also Ep. Hdt. 62: ‘For everything that is considered or grasped by an application of the mind is true' (ἐπεὶ τό γε θεωρούμενον πᾶν ἢ κατ᾽ ἐπιβολὴν λαμβανόμενον τῇ διανοίᾳ ἀληθές ἐστι).

²² See also Sext. Emp. Math. 7.203–16.

²³ See, for instance, Lucr. 4.379–468.

²⁴ See also P.Herc. 1431, col. XVI Leone.

²⁵ On the distinction between διάνοια and λόγος, see Philippson (n. 18), 571–4. On ἐπιλογισμός as the faculty that draws inferences, see G. Arrighetti, ‘Sul valore di ΕΠΙΛΟΓΙΖΟΜΑΙ, ΕΠΙΛΟΓΙΣΜΟΣ, ΕΠΙΛΟΓΙΣΙΣ nel sistema epicureo’, PP 7 (1952), 119–44; P. De Lacy, ‘Epicurean ἐπιλογισμός’, AJPh 79 (1958), 179–83; M. Schofield, ‘Epilogismos: an appraisal’, in M. Frede and G. Striker (edd.), Rationality in Greek Thought (Oxford, 1996), 221–37.

²⁶ Manuwald (n. 2), 115–20; M. Conche, Lucrèce et l᾽expérience (Villers-sur-Mer, 1981), 29–33; pace Giussani (n. 4), 176–7, Bailey (n. 4), 569, Kleve (n. 4), 111–19; J. Salem, Commentaire de la lettre d’Épicure à Herodote (Brussels, 1993), 8, 50–1. For ‘not testifying against’, see F. Bakker, Epicurean Meteorology: Sources, Method, Scope and Organization (Leiden and Boston, 2016), 15–31. The most detailed textual evidence is found in Sext. Emp. Math. 7.211–16. The related point that there can be no sense preconceptions of things that are ἄδηλα is made in D. Sedley, ‘Epicurus’ theological innatism’, in S. Fish and K. Sanders (edd.), Epicurus and the Epicurean Tradition (New York, 2011), 29–52, at 42; G. Fine, The Possibility of Inquiry: Meno's Paradox from Socrates to Sextus (New York, 2014), 236. That there are no perceptions of things that are ἄδηλα should be clear.

²⁷ Pace Giussani (n. 4), 176–7, Bailey (n. 4), 567–74. See also Sedley (n. 9), 24–5; Manuwald (n. 2), 16–20.

²⁸ See also Sandgathe (n. 4), 17–18; Asmis (n. 2), 106; Verde (n. 10), 138–40; pace Jürss (n. 2 [1991]), 76–7.

²⁹ Tsouna (n. 2).

³⁰ Diog. Laert. 10.31. For some discussion, see Muñoz Morcillo (n. 4), 144–5.

³¹ In this context, see especially the following passage in Diogenes of Oenoanda, according to which, perception (and concept formation?) is described first and foremost as the physical alteration of the perceiver's receptive organ: ‘Now the images that flow from objects, by impinging on our eyes, cause us both to see external realities and (through entering our soul, to think of them. So it is through impingements) that the soul receives in turn the things seen by the eyes; and after the impingements of the first images, our nature is rendered porous in such a manner that, even if the objects which it first saw are no longer present, images similar to the first ones are received by the mind (creating visions both when we are awake and in sleep)’ (τὰ οὖν ἀπὸ τῶν πραγμάτων ῥέοντα εἴδωλα, ἐνπείπτοντα ἡμῶν ταῖς ὄψεσιν, τοῦ τε ὁρᾶν ἡμᾶς τὰ ὑποκείμενα αἴτια γείνεται καί, εἰς [τὴν ψυχὴν εἰσιόντα, τοῦ ἐννοεῖν αὐτά. κατ᾽] ἐνπτώσεις μὲν ο[ὖν] τὰ ὑπὸ τῶν ὄψεων βλεπόμενα ἡ ψυχὴ παραλαμβάνει⋅ μετὰ δὲ τὰς τῶν πρώτων ἐνπτώσεις εἰδώλων ποροποιεῖται ἡμῶν οὕτως ἡ φύσις ὥστε, καὶ μὴ παρόντων ἔτι τῶν πραγμάτων ἃ τὸ πρῶτον εἶδεν, τὰ ὅμοια τοῖς πρώτοις τῇ διανοίᾳ δεχθ[ῆ]ναι φάσμα[τα γεννῶντα καὶ ὕπαρ] καὶ ὄ[ναρ]); fr. 9.II.9–IV.2 Smith, transl. Smith. See also P.Herc. 1431, coll. XXXIII–XXXIV Leone. The passage highlights a question in Epicurean psychology that has received only limited attention: what is the relationship between the images of perceptions and the mental images that the mind later goes on to process and think with? The topic is beyond the scope of this paper, but, for some discussion, see Jürss (n. 2 [1991]), 80–3.

³² Such a view is defended in Graver, M., ‘Managing mental pain: Epicurus vs. Aristippus on the pre-rehearsal of future ills’, Proceedings of the Boston Area Colloquium in Ancient Philosophy 17 (2002), 155–84CrossRefGoogle Scholar, at 170–7.

³³ Tohte (n. 4), 24; Rist (n. 17), 32–7; Asmis (n. 2), 86–91.

³⁴ Bailey (n. 4), 573–4; A. Long and D. Sedley (edd.), The Hellenistic Philosophers (New York, 1987), 1.90.

³⁵ πρόληψιν δὲ ἀποδίδωσιν ἐπιβολὴν ἐπί τι ἐναργὲς καὶ ἐπὶ τὴν ἐναργῆ τοῦ πράγματος ἐπίνοιαν (Clem. Al. Strom. 2.4.16 = fr. 255 Usener, transl. mine).

³⁶ The claim, made in DeWitt (n. 2), 142–50 on the strength of Cic. Nat. D. 1.43, has been thoroughly refuted: Kleve (n. 4), 23–34; Manuwald (n. 2), 11–16; Asmis (n. 2), 66–73; Jürss (n. 2 [1991]), 94–5 n. 72. For the Cicero passage as a whole as well as of how preconceptions are formed, see Tsouna (n. 2). The other main piece of textual evidence for Epicurean preconceptions is Diog. Laert. 10.33.

³⁷ See also Striker (n. 1 [1974]), 59–60 n. 3.

³⁸ ‘Perhaps a kind of concept’ because this depends on whether we also call a preconception a concept or rather a mental entity of lesser magnitude with some of the same functions as concepts.

³⁹ Glidden (n. 2), 193–4; J. Giovacchini, L'Empirisme d’Épicure (Paris, 2012), 30–1. For a reply to Glidden's identification of preconceptions and ἐπιβολαί, see J. Hammerstaedt, ‘Il ruolo della πρόληψις epicurea nell'interpretazione di Epicuro, Epistula ad Herodotum 37 sq.’, in G. Giannantoni and M. Gigante (edd.), Epicureismo Greco e Romano (Naples, 1996), 1.221–37, at 1.234–7.

⁴⁰ Sedley (n. 9), 25.

⁴¹ Konstan (n. 2 [2008]), 53; Tsouna (n. 2), 190.

⁴² Sandgathe (n. 4), 20–5; Sedley (n. 9), 13–17. For a reply to Sedley, A. Németh, Epicurus on the Self (London and New York, 2017), 134–6. Both of these proposals have shortcomings, however, since they propose a chronology of Epicurean writings by focussing on merely one technical term (ἐπιβολή or πρόληψις). Objections to Philippson (n. 4) are found in Asmis (n. 2), 88 n. 14.

⁴³ Morel (n. 2).

⁴⁴ Tsouna (n. 2), 186–93; also Konstan (n. 2 [2008]), Muñoz Morcillo (n. 4).

⁴⁵ Tsouna also adduces three further reasons. First, Epicurus makes preconceptions a criterion of truth independent from the others. If ἐπιβολή were distinct from preconceptions but needed for their functioning, then this would not make preconceptions a truly independent criterion. Second, it is not convincing that the object of ἐπιβολή is something in ourselves, given that ‘the Epicurean criteria are directed outwards, not inwards’ (Tsouna [n. 2], 191). Third, Morel's claim that ἐπιβολή is ‘a sort of assent that concerns the relation of the preconception to its object but implies no factual judgement about the world’ is implausible (Tsouna [n. 2], 192). After all, the Epicureans are concerned with truths about the world, not merely of thoughts.

⁴⁶ See also Rist (n. 17), 34.

⁴⁷ In this context, it is also apt to mention briefly Gisela Striker's reading of ἐπιβολὴ τῆς διανοίας (n. 1 [1974], 67). Distinguishing between propositions that express perceptions of specific objects of the senses such as ‘This is red’ or ‘This is sweet’ and propositions that express observable facts such as ‘This animal is a horse’ or ‘This tower is round’, Striker contends that the role of ἐπιβολὴ τῆς διανοίας is to guarantee the truth of the latter, while the former are, of course, guaranteed by simple sense perceptions. Although she herself emphasizes that she is not offering a full defence of this reading in her paper, she points to Ep. Hdt. 51 and RS 24 as textual support, which, as we saw above, stress the idea that in contradistinction to opinions, which can be true and false, ἐπιβολή is connected to the movement that leads to falsity, but is distinguished from it, being always true. Striker finally notes that a virtue of this reading is that it makes clear why later Epicureans elevated ἐπιβολή to criterial status: understood in this way, ἐπιβολαὶ seem to play a similar role as kataleptic impressions in Stoicism. While interesting, Striker's reading requires that we attribute rather significant mental content to some perceptions and presentations (namely those in which ἐπιβολαί are involved), for which there is no textual evidence. This seems to make the alternative reading of ἐπιβολαὶ as mental perceptions of different objects (for instance the gods), which was suggested above, more likely than Striker's reading of ἐπιβολή, even if it cannot be entirely ruled out. On the content of Epicurean perceptions, see also Milos, A.G., ‘Epicurean conceptual content’, Prolegomena 14 (2015), 167–91Google Scholar; Bown, A., ‘Epicurus on truth and falsehood’, Phronesis 61 (2016), 463–503CrossRefGoogle Scholar; Verde, F., ‘Ancora sullo statuto veritativo della sensazione in Epicuro’, Lexicon Philosophicum 6 (2018), 79–104Google Scholar.

⁴⁸ Tsouna (n. 2), 213–15; pace Asmis (n. 2), 124.

⁴⁹ Margret Graver (following Rudolf Kassel) suggests that Cicero also uses reuocatio (‘recall’) as an equivalent of ἐπιβολή, and points out that he frequently uses intueor (‘give attention to’) to express the same idea ([n. 32], 170–2). Lucretius does not use intueor in On the Nature of Things and, if he uses reuocatio, it is either in a non-technical sense or in a sense not related to any kind of mental act. Accordingly, we should be suspicious of whether Cicero really refers to ἐπιβολαί when he uses reuocatio; furthermore, in so far as Philodemus expresses some of the same ideas that Cicero does in the passages Graver adduces, it seems unnecessary to scrutinize these passages in more detail.

⁵⁰ The Latin text of Lucretius is taken from J. Martin, T. Lucreti Cari De rerum natura libri sex (Leipzig, 1969). The translations are taken from M.F. Smith, Lucretius. On the Nature of Things (Indianapolis and Cambridge, 2001).

⁵¹ Lucr. 2.124, 2.745, 4.476, 4.479, 4.854, 5.124, 5.182 and 5.1047. See also Glidden (n. 2), 179.

⁵² The Latin text and the English translation are taken from H. Rackham, Cicero: On the Nature of the Gods, Academics (Cambridge, MA and London, 1951²).

⁵³ In addition, ἐπιβολή is also used in the Epicurean ethical treatise preserved in P.Herc. 346, a text which cannot be with certainty ascribed to any Epicurean author, even if its latest editor cautiously suggests Philodemean authorship: M. Capasso, Trattato etico epicureo (PHerc. 346) (Naples, 1982), 31–40. In this text, we read: ‘and it is fitting for us, dear friends, that we do what is the characteristic of wisdom at all times, always on the basis of the particular circumstances, and that we bring about the characteristic application (of the mind)’ (καὶ ἡμῖν προσήκει, ὦ φίλ[οι ἄ]νδρες, τὸ σοφίας ἴδιον ἐργαζομένους ἐν παντὶ καιρῶι τ[αῖ]ς ἰδι[ό]τησιν ἀεὶ τῶν συ[μ]βεβηκότων καὶ ἐπι[βο]λὰς ἰδία[ς π]οιουμένους; P.Herc. 346, col. IV.10–15 Capasso, transl. mine). Here, ἐπιβολή seems to be an act of attention, an inner attitude needed to make a wise action appropriate. Later in the text (col. IV.25–6), the author refers to an ἀθρόα ἐπιβολή, and so introduces the same contrast that we already found at Ep. Hdt. 35 (discussed above).

⁵⁴ A similar usage is found in Philodemus’ On Music Book 4 col. CXXIX.1–7 Delattre (transl. mine): ‘Music is also not able to soothe misfortunes in love, for such is the task of reason alone, but it makes us inattentive by diverting us just as sexual pleasures and drunkenness' (καὶ μὴν οὐδὲ παραμυθεῖσθαι δύναται μουσικὴ τὰς ἐν ἔρωτι δυσπραξίας—λόγου γὰρ μόνου τὸ τοιοῦτον—, ἀλλ᾽ ἀν⟦α⟧επιβλήτους ποιεῖ περισπῶσα καθάπερ ἀφροδ⟦ε⟧ίς[ι]α καὶ μέθη).

⁵⁵ In another passage of Philodemus’ On the Gods Book 3 the original text speaks of mental perceptions, but this was then corrected to preconceptions: ‘And we could not suppose (or, grasp) any living thing thought of in accordance with the preconception (or, with the mental perception) that could be completely deprived of these things, but also (or, and) … (καὶ ⟦φαντας⟧`προληπ΄-τικῶς νοούμεν[ο]ν ζῷον οὐδὲ[ν ἐ]δυνάμεθα `ὑπο΄[λ]αβεῖν [ἐ]στερημένον ὅλως αὐτῶν, `ἀλλὰ΄ καὶ[’ (fr. 26.3–5 Wigodsky, i.e. M. Wigodsky, ‘Emotions and immortality in Philodemus On the Gods 3 and the Aeneid’, in D. Armstrong, J. Fish, P.A. Johnston and M.B. Skinner [edd.], Virgil, Philodemus, and the Augustans [Austin, 2004], 211–28, at 216, with Wigodsky's translation, modified). In the Greek text just quoted, ⟦ ⟧ indicate an older version of the text, ` ΄ the corrections. It is unclear, unfortunately, how exactly these corrections are to be evaluated, even if the papyrus in question actually were Philodemus’ master copy, as is sometimes assumed: Essler, H., ‘P.Herc. 152/157 – an author's master copy’, S&T 15 (2017), 57–80Google Scholar, especially 74.

⁵⁶ Tsouna (n. 2), 214.

⁵⁷ Tsouna (n. 2), 213.