We commonly distinguish between subjective impressions and objective truth. The words subjective and objective are constantly recurring throughout the history of philosophy, and as this is the first time I use them, I will explain them here. In every act of thought there must necessarily be two terms. I am now looking at this desk and thinking of this desk. There is the "I" which thinks, and there is the desk which is thought. "I" am the subject of the thought, the desk is the object of the thought. In general, the subject is that which thinks, and the object is that which is thought. Subjective is that which appertains to the subject, and objective is that which appertains to the object. So the meaning of the distinction between subjective impressions and the objective truth is clear. My personal impression may be that the earth is flat, but the objective truth is that the {115} earth is round. Travelling through a desert, I may be subject to a mirage, and think that there is water in front of me. That is my subjective impression. The objective truth is that there is nothing but sand. The objective truth is something which has an existence of its own, independent of me. It does not matter what I think, or what you think, what I want, or what you want; the truth is what it is. We must conform ourselves to the truth. Truth will not conform itself to our personal inclinations, wishes, or impressions. The teaching of Protagoras practically amounted to a denial of this. What it meant was that there is no objective truth, no truth independent of the individual subject. Whatever seems to the individual true is true for that individual. Thus truth is identified with subjective sensations and impressions.