If Thought is capable of being classed with Electricity, or Will with chemical affinity, as a mode of motion, it seems necessary to fall at once under the second law of thermodynamics as one of the energies which most easily degrades itself, and, if not carefully guarded, returns bodily to the cheaper form called Heat. Of all possible theories, this is likely to prove the most fatal to Professors of History.

I hate photographs abstractly, because they have given me more ideas perversely and immovably wrong, than I ever should get by imagination.

[P]olitical and social and scientific values ... should be correlated in some relation of movement that could be expressed in mathematics, nor did one care in the least that all the world said it could not be done, or that one knew not enough mathematics even to figure a formula beyond the schoolboy s=(1/2)gt2. If Kepler and Newton could take liberties with the sun and moon, an obscure person ... could take liberties with Congress, and venture to multiply its attraction into the square of its time. He had only to find a value, even infinitesimal, for its attraction.

To my fancy, one looks back on life, it has only two responsibilities, which include all the others: one is the bringing of new life into existence; the other, educating it after it is brought in. All betrayals of trust result from these original sins.

As history stands, it is a sort of Chinese play, without end andl without lesson. With these impressions I wrote the last line of my History, asking for a round century before going further.

Young men have a passion for regarding their elders as senile.

He never labored so hard to learn a language as he did to hold his tongue, and it affected him for life. The habit of reticence — of talking without meaning — is never effaced.