TIDA is based on the following hypotheses:
1. The soul is the principle of the science of living things. A major hypothesis in current scholarship is that the De anima falls into the domain of philosophy of mind, understood as the philosophical account of the phenomena of the mental. Against this, TIDA claims that the De anima is dedicated only to the definition of the first principle of living beings — which principle Aristotle calls ‘the soul’. However, figuring out the principles of a science, for Aristotle, is an investigation that is methodologically separate from the explanations that are given with reference to these principles: the ‘road to the principles’ ought not to coincide with the ‘road from the principles’, on pain of circularity. As a result, we should not necessarily expect to find Aristotle’s scientific explanations of mental phenomena in the De anima.
2. Stages of inquiry. The second working hypothesis is that there are stages of inquiry on Aristotle’s way to the principles as well as from the principles. Working hypotheses (3) and (4) correspond to different stages of Aristotle’s inquiry into the soul in the De anima.
3. Psychological hylomorphism and Aristotle’s theory of the soul. Psychological hylomorphism is not the main message of the De anima. The third working hypothesis is that Aristotle’s famous application of the hylomorphic framework to the soul body – relation in De anima II 1 is not yet his theory of the soul, but only a general constraint on any account of the soul, including his own. Psychological hylomorphism is the general framework within which Aristotle will present his account of the soul to follow; it is not yet a theory of the item that is supposed to play the role of the essential form, and the first principle of the science, of living things.
4. Aristotle’s theory of the soul may exceed the De anima. Our fourth working hypothesis is that Aristotle’s account of the soul as the set of basic capacities of living things as outlined in De anima II 2 sqq. marks the beginning of his theory of the soul (in the above sense of a theory of the item that is the essential form of living things). However, this theory may exceed the boundaries of the De anima given that the definitions of the powers of the soul in this treatise may not suffice to deliver Aristotle’s full theory of the soul. His full theory may also include the account of the workings of the soul in the living body as it is given in the works “common to body and soul”. The doctrine of cardiocentrism and the localization of the perceptual soul in the heart of the living animal thus may be in some sense part of Aristotle’s theory of the soul.
5. Mental phenomena in the Parva naturalia. A fifth working hypothesis is that mental phenomena become a central concern for Aristotle not so much in the De anima itself as in his studies of how the powers of the soul are exercised in the living body. Hence, the Aristotelian analogue of what we post-Cartesians nowadays call the mind is mainly to be found in his treatment of the embodied cognitive soul in his works “common to body and soul”.
6. The actual soul is the embodied soul. Our sixth hypothesis is that embodiment of the soul is implied from the change of perspective adopted in the Parva where we study what is common to the body and the soul. This means that the soul becomes real only when it is actualized in a body (second actuality).
7. Qualitative physics. Our seventh hypothesis is that Aristotle has a qualitative physics. This is a physis that not only accepts qualities as respectable entities of nature but that also endorses the idea that qualities are causally efficacious. TIDA wishes to explore the explanatory potential of Aristotle’s qualitative physics in the context of his scientific account of mental phenomena.