But logic tells us nothing about whether for each object nature must also show many others that can be compared with it in similarity of form; on the contrary, this condition for the possibility of applying logic to nature is a principle of representing nature, as system for our power of judgement, in which the manifold, divided into genera and species, makes it possible for us, through comparison, to bring all the forms of nature that we may encounter to concepts (of greater or lesser generality).