The ideal, without doubt, varies, but its enemies, alas, are always the same.
My pessimism extends to the point of even suspecting the sincerity of other pessimists.
There are things that don't deserve to be said briefly.
When a scientist is ahead of his times, it is often through misunderstanding of current, rather than intuition of future truth. In science there is never any error so gross that it won't one day, from some perspective, appear prophetic.
Take heed of critics even when they are not fair; resist them even when they are.
Whether man is disposed to yield to nature or to oppose her, he cannot do without a correct understanding of her language