Like Plato, we may occasionally feel that we have caught a glimpse of the super-sensible world unveiled; but it disappears as the senses regain their hold. We can probably fix a firm eye on one term of reason, and criticise its value: but it is less easy to survey the Bacchic dance from term to term[7], and allow them to criticise themselves. The distracting influence of our associations, or of outside things, is always leading us astray. Either we incline to treat thoughts as psychological products or species, the outcome of a mental process, which are (_a_) given to us from the beginning, and so _a priori_ or innate, or which (_b_) spring up in the course of experience by mutual friction between our mind and the outside world, and so are _a posteriori_ or derivative. Or disregarding the subjective side of thoughts, we act as if they were more correctly called things: we speak of relations between phenomena: we suppose things, and causes, and quantities to form part of the so-called external universe, which science explores. The one estimate of thought, like the other, keeps in view, though at some distance, and so as not to interfere with their practical discussions, the separate and equal existence of thoughts and things. The psychologists or subjectivists of logic scrutinise the world within us first of all, and purpose to accomplish what can be done for the mind as possessing a faculty of thought, before they turn to the world of things. The realists or objectivists of logic think it better for practical work to allow thought only the formal or outside labour of surveying and analysing the laws of phenomena out of the phenomena which contain them. Neither of them examines thought--'the original synthetic unity'--in its own integrity as a movement in its own self, an inner organisation, of which subject and object, the mind and the things called external, are the vehicles, or, in logical language, the accidents.