Theme 1: Theory of knowledge and theory of science (before lecture)

In the preface to the second edition of "Critique of Pure Reason" (page B xvi) Kant says: "Thus far it has been assumed that all our cognition must conform to objects. On that presupposition, however, all our attempts to establish something about them a priori, by means of concepts through which our cognition would be expanded, have come to nothing. Let us, therefore, try to find out by experiment whether we shall not make better progress in the problems of metaphysics if we assume that objects must conform to our cognition." How are we to understand this?

With this part of the second preface, Kant establishes a new perspective on the relation between cognition and objects. Hitherto, existing objects determined human cognition (i.e. knowledge was established a posteriori, based on experience with the object). Kant, however, wants to reverse the relation so that objects have to conform to our cognition (i.e. concepts get established a priori, independent of experience). He suggests that this approach leads to better progress in metaphysics, especially because (during his time) it was a discipline only focusing on rather big and abstract matters, such as being, knowledge and the real nature of things (cf. Encyclopaedia britannica). 

This approach had already been successful before, as Kant's example of Copernicus and the change to the heliocentric system (cf. Encyclopaedia britannica) proves. Kant really wants to encourage what we nowadays call "thinking outside the box" which helps to open our minds and broaden our horizons so that we can approach questions and problems in unconventional ways and thus discover new solutions and answers. 

In my opinion, there needs to be a combination of the two approaches, the relation and influence between cognition and objects or any other abstract form of problem have to be both ways. Copernicus, to stick with Kant's example, could also only be successful with his a priori approach because he already had a posteriori knowledge about the topic. One could even argue that all a priori cognition is based on some kind of a posteriori knowledge about the object or matter at hand or at least about its context. Even if a priori assumptions are made on completely new ideas and abstract concepts (such as metaphysics in Kant's time), they derive from a posteriori knowledge providing information about the in-existence of the idea and on related predecessors leading to this idea. 

At the end of the discussion of the definition "Knowledge is perception", Socrates argues that we do not see and hear "with" the eyes and the ears, but "through" the eyes and the ears. How are we to understand this? And in what way is it correct to say that Socrates argument is directed towards what we in modern terms call "empiricism"?

In Plato's dialogue between Socrates and Theaetetus, Socrates introduces the thought that the sensory organs - in this case the ears and the eyes - are mere transmitters of sensations and experiences. The difference between hearing or seeing through and not with them emphasises the processing of impressions in "the mind, or whatever we please to call it" (cf. Plato, Theaetetus, p. 329 (epub)) into a cognition or knowledge. If we would hear with our ears, that would mean that the mind would only be a receiver of information and the active part would be the ears' responsibility. Both Socrates and Theaetetus disagree with this because they believe that the senses are instruments of the mind which it uses to perceive experiences in its surroundings. Rephrasing this with Kant's a priori/a posteriori concept, this consequently means that the mind has to rely on the senses, its instruments, for a posteriori cognition which is based on experiences perceived through them. A priori cognition or assumptions, however, (for the moment neglecting my earlier argument of the questionable existence of a priori cognition without a posteriori cognition) originate from the mind and can then be examined with the use of the senses. This combines Plato (or Socrates in his dialogue) and Kant into our modern empirical scientific methods which also aim at proving hypotheses (a priori assumptions originating from the mind) with the help of research methods such as observation (a posteriori cognition perceived through the senses). 

Also the philosophical concept of empiricism ( = "the view that all concepts originate in experience [...] or that all rationally acceptable beliefs or propositions are justifiable or knowable only through experience" cf. Encyclopaedia Britannica) can be connected to what Socrates suggests, that we perceive our experiences through our sensory instruments and turn them into concepts and beliefs. Empiricism assumes that everything (also Kant's a priori assumptions) derives from experiences previously perceived through the senses, which supports my earlier argument of all a priori cognitions deriving from a posteriori ones. Socrates also argues into that direction in the dialogue as they talk about how the mind can differentiate between sounds and colours which cannot neutrally be perceived by the sensory organs but are established as a posteriori concepts by and in our minds. This can be seen as a first step towards philosophical empiricism. 

To sum it up, I think that Plato and Kant discuss very similar approaches to the relation of objects or experiences and our cognition and the establishment of principles. Nonetheless, Kant takes it a step further. Plato describes, to use Kant's later concept, only the existence of a posteriori cognition. Kant on the other hand also introduces a priori concepts which seem to be a better approach to him. I would argue again that even though there is a definite distinction between the two, a priori knowledge cannot exist without any previous existence of a posteriori knowledge.