Psychology saves us from mistakes. It makes us more clear as to what we are about. We gain confidence in respect to any method which we are using as soon as we believe that it has theory as well as practice at its back.

We [may] answer the question: "Why is snow white?" by saying, "For the same reason that soap-suds or whipped eggs are white"-in other words, instead of giving the reason for a fact, we give another example of the same fact. This offering a similar instance, instead of a reason, has often been criticised as one of the forms of logical depravity in men. But manifestly it is not a perverse act of thought, but only an incomplete one. Furnishing parallel cases is the necessary first step towards abstracting the reason imbedded in them all.

The perfect stillness of the night was thrilled by a more solemn silence. The darkness held a presence that was all the more felt because it was not seen. I could not any more have doubted that HE was there than that I was. Indeed, I felt myself to be, if possible, the less real of the two.

Truth, as any dictionary will tell you, is a property of certain of our ideas. It means their agreement, as falsity means their disagreement, with reality.

Every time a resolve or a fine glow of feeling evaporates without bearing practical fruit is worse than a chance lost; it works to hinder future resolutions and emotions from taking the normal path of discharge. There is no more contemptible type of human character than that of the nerveless sentimentalist and dreamer, who spends his life in a weltering sea of sensibility and emotion, but who never does a manly concrete deed.

Theory must mediate between all previous truths and certain new experiences

The union of the mathematician with the poet, fervor with measure, passion with correctness, this surely is the ideal.