In its decree Optatam Totius (On Priestly Training) Vatican II required that ‘In order that students for the priesthood may illumine the mysteries of salvation as completely as possible they should learn to penetrate them more deeply with the help of speculation, under the guidance of St. Thomas [Aquinas], and to perceive their interconnections’ (§16). In his encyclical Fides et Ratio John Paul II also stressed this point, qualifying it by saying ‘the Church has no philosophy of its own’. Yet in this twenty-first century with its post-foundationalism there is still radical disagreement among scholars, even Catholic ones, about the validity of Thomistic metaphysics, the very heart of St. Thomas’ philosophical thought.

A major effort to meet this problem has recently been supplied by a theologian at the Dominican House of Studies in Washington D.C., Thomas Joseph White. In his Introduction and Part I White explores the accusation by Martin Heidegger that any ‘metaphysics’, such as that of Aquinas, finally collapses into a Kantian ‘ontotheology’, in which all concepts and principles are purely mental inventions. (This view is supported by and supports the current popularity of such atheistic books as Richard Dawkins’ The God Delusion (2006) and the physicist Victor J. Stenger's God: The Failed Hypothesis (2007)). White's book, with its extensive bibliography, is a very penetrating Thomistic defense of the existential validity of metaphysics and of a metaphysical natural theology.

Part II deals with Aristotle's break with Plato and concludes ‘In contrast to Heidegger's characterization of ontotheology…the logos of Aristotelian metaphysics is not reducible to the techne of rhetoric — a discourse constructed for merely instrumental and political ends’ (p.  66). White then asks whether Thomas, although he certainly follows Aristotle, differs from him (1) in thinking always in a theological context; (2) in denying that, as Aristotle seems to think, since the universe exists necessarily, God is not truly a Creator in the biblical sense; (3) in emphasizing that there is not only an analogy of proportionality (A is to B as C is to D) between imperfect creatures and a perfect First Cause, and also a causal analogy of attribution of creatures to God of the multa ad unum type, but also of the ad alterum type. Analogy of attribution ad unum is a set of relations of many effects to a single cause such as the ten Aristotelian categories have to ens commune, but is ad alterum when nine categories of properties other than substances are considered as the effects of the single category of substance. If for Aristotle the relation of lesser beings is only one of the attribution multa ad unum, then for him God again is not, as for Aquinas, strictly speaking the Creator. (4) ‘How can a Thomist attain demonstrative knowledge of God that is analogical, based upon a causal study of the beings we experience?’ (5) Can the human person supply an analogy to God with respect to intelligence and will? Some historians think that Aristotle held that since God is ‘Thought Thinking Itself’ God does not know the universe that he causes. White admits these obscurities in the Aristotelian texts as we have them, but holds, as I would do, that Aquinas clarifies them in important ways.

Moving in Part III to twentieth-century interpretations of Thomas, White deals very effectively with the existentialist views of Etienne Gilson, known for his opposition to the Louvain transcendental Thomism that was better known to Heidegger. From 1929 to his death in 1979 Gilson headed the Medieval Institute of Toronto and his anti-Aristotelian interpretation of Thomism as rooted in the ‘judgment of esse’ has predominated in Canada and the USA, especially through John Wippel at the Catholic University of America. White concludes that the more Gilson separated Thomism from Aristotelianism and placed its ‘analysis in the service of the defense of Christian teaching within theology’, the more his view also became liable to what Heidegger attacked as ontotheology.

Next White discusses Jacques Maritain's view that Thomist philosophy is rooted in an ‘intuition of being’, a theory familiar to me personally from a brilliant disciple of Maritain's, my revered teacher Yves Simon of the Universities of Notre Dame and Chicago. White applauds Maritain's ‘personalism’ but claims (pp.  156f) that it is ‘a philosophical exposition of metaphysics [that] lacks a study of the intrinsic causes of being qua being, meaning a study of the substance and actuality as the formal and final causes of a thing's existing’. This criticism I deal with below.

Then White takes up the personalism of the Jesuit thinkers Joseph Maréchal and Karl Rahner, in which the human person is a ‘Being-Toward Truth’ and concludes (p.  198) that ‘suggestive as Rahner's thought is, it leaves unresolved the question of in what way really (if at all) human spiritual acts of knowledge and love are analogous to the transcendent wisdom and love of God’.

In Part IV White gives his own reading of Aquinas (pp.  206–216), which he opposes in detail to that given by Ralph McInerny in his Praeambula Fidei: Thomism and the God of the Philosophers (2006) and my own The Way Toward Wisdom: An Interdisciplinary and Contextual Introduction to Metaphysics (2006). We and others hold that there would be no science of metaphysics (as Aristotle shows in Physics VIII and Aquinas in his commentary expounds without dissent) unless natural science (physica which Aquinas never separates from the ‘philosophy of nature’) has first proved the existence of spiritual beings, including the First Uncaused Cause. White admits (pp.  206–210) that this position is a ‘reasonable viewpoint’, but finds it ‘insufficient or problematic’ for six reasons.

First, it is contrary to many statements by St. Thomas: Quod primo cadit in intellectu est ens —‘what first falls under the intellect is being’. White admits, however, that many notions such as substance and the categories are first grasped intellectually only in a ‘vague embryonic way…from the time of our initial experiences of the world’. Thus it is not sufficient to form a valid metaphysics that we have a vague intuition that immaterial as well as material causes exist. Throughout all human cultures there are beliefs in spiritual realities, but only with Greek philosophy (and perhaps later the philosophies of India) did these become sufficiently defined as to make them principles of strict demonstration in an analytic discipline. Unfortunately this historic fact undercuts White's position as well as those of Gilson and Maritain.

Second, White argues that natural science depends on metaphysics for its own principles. I grant of course that it is a task of metaphysics, once its validity has been demonstrated, to review the definitions and principles of all the inferior sciences by relating them to each other. But for Aristotle and Aquinas it can do this demonstratively only after natural science has first established that a First Non-material Uncaused Cause of motion, change, causality, and the categories has been demonstrated to exist. Metaphysics reflects on the findings of the other disciplines; it does not demonstrate them. Yet its proper object, according to Aquinas, is not God, but ens commune and the transcendentals, such as One, True and Good, analogically found in all the sciences. God, on the contrary, as Aquinas shows in the Proemium of his Commentary on the Metaphysics, is not included in the formal object of metaphysics, but is its goal. Aristotle in the Physics established these principles from sense experience from the sensible fact of motion, while in the Metaphysics he compares and distinguishes their analogical meanings in all the analytic disciplines. Therefore Metaphysics is called First Philosophy not because it is first known, but on the contrary it is last known and should be studied only after the other disciplines because it is a reflection and comparison of their respective findings.

Recently the noted physicist Anthony Rizzi, Director of the Institute for Advanced Physics (cf. www.iapweb.org), in The Science Before Science (2004) and Physics for Realists (2008), has shown that modern science can in fact establish the validity of Aquinas’ metaphysics if it is understood in a truly empirical way, rather than as what Maritain calls an ‘empiriological’ way, that is, as merely a set of mathematical models that can be used dialectically in research but that can never be precisely and positively demonstrative. Aristotle and Aquinas admitted that such a ‘mixed science’ has research value, but because its explanations are only dialectical it cannot ground metaphysics. Rizzi goes beyond Maritain, however, in proposing to rethink modern science on the basis of Aristotle's realistic and demonstrative Physics. This need in no way neglect the value of modern scientific theories, including evolution, but reconciles its dialectical theories with a genuine science of nature. It is this direction that I also believe Thomism should take in order for it to reconcile modern science and the Catholic Faith, a major task recognized but not solved by Vatican II. White does not deal with this promising project.

White's third point is that ‘the proposal that the object of metaphysics is provided by natural philosophy insofar as the latter yields a demonstration of immaterial substance, flies in the face of Aquinas’ explicit proposals.’ He then refers to many texts where Aquinas speaks of immaterial substances from a metaphysical viewpoint, but I have already admitted this. Moreover, White does not explain why Aristotle's Physics and Aquinas’ commentary, which both these authors say should be studied before metaphysics, avoids any demonstrations not directly based on sense experience. Again White simply assumes that the Physics VIII proof of the existence of a First Cause is metaphysical not physical.

The fourth point raised by White is that ‘no proper analogy for transcendent being is possible if there is not initially some knowledge of being as a proper object given in common human experience’. He means by this that ‘at the very least, these notions [motion, subsistence, actuality, potency] as they are employed in the Physics are already implicitly metaphysical, and become in some sense explicitly so even at the term of the argumentation of Aristotle's (and Aquinas’) natural science. If this were not the case, not only would the final primary mover of Aristotle's Physics literally be unthinkable, but also any possible metaphysics of God would disseminate into unintelligible polysemy. From terms taken from the physical world, we could derive only a purely equivocal language for the divine’. This objection takes us back to White's first point. I would note, however, that while to declare that an Unmoved First Cause of natural motion exists and is the cause of the existence of all natural motions requires us to admit that such a First Cause is only analogically a ‘cause’, this, however, does not result in pure equivocation but in an analogy of attribution ad alterum, as White rightly insists, and then consequently in analogies of proportionality, as many other Thomists have shown.

White's fifth criticism of McInerny's and my views is ‘[I]f we cannot know being conceptually from the start based upon direct experiences, we never will come to know this object through purely mediate and non-experiential philosophical demonstrations’. This objection is really the same as the first point above. The Aristotelian view against Plato that Aquinas accepted, and McInerny and I defend, is that all our natural knowledge is based on sense experience. In every demonstrative discipline, however, the definition of terms and the principles of that science are abstracted from this direct sense knowledge as material being in its essentia and its correlative esse, either in a vague or in a scientific way. Thus the scientific fact of the existence of material being would be true even if there were no immaterial beings, although in fact by arguing from effect to cause Aristotle in Physics VIII shows this is not the case.

White's sixth point is that our ‘textual citations of Aquinas to the effect that without the demonstrations of immaterial substance natural science would be ‘first philosophy’ are not entirely transparent. Equally reasonable alternative interpretations of these passages exist’. This also reduces to White's first point, since for him the fact that a term is ‘real’ and not merely ‘logical’ means that it is implicitly metaphysical, while for McInerny and me this merely means it is known in a vague common sense way and not in a demonstrative, scientific way, which is what is required to have a demonstrative discipline of metaphysics. White seems to admit my position is valid (p.  216), but wants also to leave room for his position which is the subject of his book that seeks to dialogue with current thought. He has in fact left metaphysics without a defense in the face of modern science and today such a valid defense is what is sorely needed. Without it the harmony between reason and Christian faith John Paul II calls for in his encyclical Veritatis Splendor remains dubious. If Thomists are to maintain the light of St. Thomas in the service of theology and the Church we must face up to the confusions produced by the mathematicism of modern science that has become a set of technologies that are practically very effective but intellectually obscure. Therefore we need not only to attack the Heideggerian claim that St. Thomas’ metaphysics is nothing but a Kantian ontotheology but must first establish that it is itself valid because founded in the directly empirical principles of natural science.

Too often it is forgotten that the distinction of ‘science’ from ‘philosophy’ is not Thomistic. For Aquinas ‘philosophy’ included all the rational disciplines. These were analogically united and clarified, first by a comparison of their terms and then by their relation to a non-material First Cause by ‘First Philosophy.’ This came to be called (probably by the editors of the Aristotelian corpus) ‘metaphysics.’ Such terms as ‘psychology’, ‘ontology’, and ‘epistemology’, were introduced into Neo-Scholasticism by the German Protestant hypnotist (!) Rudolph Glocenius (1547–1628). They came to influence the Thomism of Leo XIII's Revival through the textbooks of the Enlightenment thinker Christian Wolff (1679–1754). Wolff divided ‘empirical psychology’ from ‘rational or philosophical psychology’ and thus initiated the modern separation in our universities of ‘science’ from ‘philosophy’ and the classifying of the latter with the ‘humanities’ as against the ‘sciences.’ Regrettably White's helpful book, like so many others on the subject, is still caught in Wolff's confused terminology and his Neo-Scholastic division of the sciences.