This last is by far the greatest change which has ever occurred in the history of evolution. In organic evolution Nature operates by necessary law without the conscious voluntary co-operation of the thing evolving. In human progress man voluntarily co-operates with Nature in the work of evolution, and even assumes to take the process mainly into his own hands. Organic evolution is by _necessary_ law, human progress by _free_ or at least by freer law. Organic evolution is by a _pushing_ upward and onward from _below_ and _behind_, human progress by a _drawing_ upward and onward from above and in front by the attractive force of ideals. In a word, organic evolution is by the law of _force_, human evolution by the law of _love_. It may be well to stop a moment and show briefly some of the differences between organic and human evolution--differences which are, of course, wholly the result of the introduction of this new factor: 1. In organic evolution “_the fittest_” are those most in harmony with the physical environment, and therefore they survive. In human evolution _the fittest_ are those most in harmony with _the ideal_, and often, especially in the early stages, when the race is still largely under the dominion of organic factors, they do not survive, because not in harmony with the social environment. But, although the fittest individuals may indeed perish, the _ideal_ survives in the race and will eventually triumph. 2. In organic evolution the weak, the sick, the helpless, the unfit in any way perish and _ought to perish_, because this is the most efficient way of strengthening the _blood_ or _physical nature_ of the species, and thus of carrying forward evolution. In human evolution the weak, the helpless, the sick, the old, the unfit in any way are sustained and _ought to be sustained_, because sympathy, love, pity, strengthen the _spirit_ or _moral nature_ of the race. But let us remember that in this material world of ours and during this earthly life the spirit or moral nature is conditioned on the physical nature; and, therefore, in all our attempts to help the weak we must be careful to avoid poisoning the blood and weakening the physical vigor of the race by inheritance. This gravest of social problems, viz., How shall we obey the higher law of love and mutual help without weakening the _blood_ of the race by inheritance and the spirit of the race by removing the necessity of self-help?--this problem, I believe, can and will be solved by a _rational education_, physical, mental, and moral. I only allude to this. It is too wide a field to follow up here.