Note 11 — INTRODUCTION

It has been thought a doubtful point that my divisions in pure Philosophy should always be threefold. But that lies in the nature of the thing. If there is to be an a priori division it must be either analytical, according to the law of contradiction, which is always twofold (quodlibet ens est aut A aut non A); or it is synthetical. And if in this latter case it is to be derived from a priori concepts (not as in Mathematic from the intuition corresponding to the concept), the division must necessarily be trichotomy. For according to what is requisite for synthetical unity in general there must be (1) a condition, (2) a conditioned, and (3) the concept which arises from the union of the conditioned with its condition.