Liberty and Aggression [Liberty, February 2, 1889.] My dear Mr. Tucker:(19 ¶ 1) Liberty has done me a great service in carrying me from the metaphysical speculations in which I was formerly interested into a vein of practical thought which is more than a mere overflow of humanitarianism; which is as closely logical and strictly scientific as any other practical investigation. In spite of certain small criticisms which it would be petty to dwell upon, it is the most advanced and most intellectual paper that I have seen. I esteem it most highly.(19 ¶ 2) The particular matter upon which we have exchanged letters—...