The good is often defined as that which conduces to some end; but an end is nothing other than something willed; that which conduces to an end is the cause of something that is willed, so that this explanation also refers back to a consciousness. Whatever is existent for us must be existent in us, in our consciousness. Our states of consciousness are either painful, or indifferent, or pleasant. We must turn, therefore, in the last analysis, not to things, but to the mind, if we wish to distinguish what is good and what is bad; and according to the differing constitution of different minds, the same things may be good or bad. There is good and bad with respect to our body or senses, and good and bad with respect to our mind. A moral good is one which causes conscious states of moral satisfaction. The good has often been divided into the useful and the agreeable. The agreeable is that which causes immediate, the useful that which causes mediate pleasure. A thing may be both useful and agreeable; and the like is true of the disagreeable and the harmful. The useful and the harmful in this, as it were inner, (subjective) sense, are to be distinguished from the useful and the harmful in an objective sense; in the last sense, that is useful which tends to the preservation of life. Between the useful and harmful, and the pleasurable and painful, in this sense, there must exist, as the theory of evolution teaches us, a wide-reaching correspondence. Living beings do that which is pleasurable to them; they avoid that which is painful; they continue alive when they do that which is conducive to life and avoid that which is harmful to life. This continuous process of exterminating those beings to whom the harmful is agreeable and the useful painful, must tend to make the harmful coincide with the painful, and the useful with the pleasurable. The agreement is, however, far from being a perfect one; and it is the less so, the more complicated are the conditions of life. It is the most imperfect in human beings. Good is that which causes pleasure or prevents pain; that is better which causes more pleasure or prevents more pain. A thing may cause both joy and pain; in this case, the excess decides whether a thing is good or bad; and the greater the excess, the better or the worse is the thing. The greatest possible excess of satisfied states of consciousness in the life of a human being one may call his greatest possible happiness. The greatest possible happiness is hence the standard by which good and evil are determined. From these reflections is to be seen that a distinction is to be made between that which is _desired_ and that which is _desirable_. All that is desired is pleasurable, yet much that is pleasurable has pain for its result,--pain that is far greater than the momentary pleasure.