Eternity is undeniably a property of the existence of the absolutely infinite substance. Does this mean that it exclusively belongs to divinity? Whatever the case may be, if it belongs to God because its essence involves existence, it seems inappropriate to attribute this quality to a being whose essence only involves possible existence. It is for this reason, incidentally, that Spinoza puts forth a distinction between duration and eternity. ‘From our earlier division of being into being whose essence involves existence and being whose essence involves only possible existence, there arises the distinction between eternity and duration.’ Strictly speaking, eternity is the prerogative of substance and is deduced from the necessary character of its existence. At the same time, ‘created things’, according to the terminology of Metaphysical Thoughts, are said to endure and not go on forever (s’éterniser). They cannot, strictly speaking, be called eternal. Spinoza is very clear on this point. ‘Infinite actual existence pertains to God in the same way as infinite actual intellect pertains to him. And I call this infinite existence Eternity, which is to be attributed to God alone, and not to any created thing, even though its duration should be without beginning or end.’ How, then, can he affirm the eternity of the human mind in the Ethics? Does this constitute a shortcoming in the vocabulary, as an observation in Metaphysical Thoughts would suggest? ‘We are accustomed, on account of a defect of words, to ascribe eternity also to things whose essence is distinguished from their existence, as when we say that it does not involve a contradiction for the world to have existed from eternity; also we attribute eternity to the essences of things so long as we conceive the things as not existing, for then we call them eternal.’ Or is it rather a change in perspective, as the development in vocabulary would suggest? Keeping with his principles, Spinoza reserves the term eternity for God and attempts to demonstrate the mind's immortality. Yet, in the Ethics, he will no longer speak of the mind's immortality, but rather of its eternity. Must we then interpret this change as a misuse of language or as the definition of a real eternity?