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.
The good is often considered as opposed to the agreeable, and the bad as opposed to the disagreeable or painful. In this case, by pain and pleasure are understood feelings of the moment, by good and bad are understood enduring, or at least long-continuing causes of lasting or oft-recurring pain or pleasure; momentary pleasure may be bought at the expense of long suffering; and short pain may be the condition of the prevention of greater evil.
A thing may be good as regards one individual, bad as regards another. A thing is truly good as regards a society when its total effect has for the society lasting beneficial results, that is, accords with the happiness of the society during its whole existence; and that is for mankind truly good which is, in its total effect, beneficial to present and future humanity.
In general, we may say that, when we order our conduct by the thought to serve mankind to the best of our ability, we have a satisfied consciousness, a good conscience. In so far, therefore, a noble deed is good for ourselves as well as for society. The question whether or not the performance of our duty corresponds to our greatest possible happiness, is a different one. But the good man does not allow this thought the chief role in consciousness; he is filled with the thought of doing his duty in devoting himself to the happiness of mankind, and there is but one form of his own happiness which he will not forego, namely, the blessedness of a good conscience. This consciousness, this blessedness which unites the human being to mankind, he should regard as his highest good; for it is a moral good; and the dissatisfaction which lies in the consciousness of having violated his duty towards mankind he should regard as the greatest evil.
It may be objected that this morally satisfied consciousness, this sort of joy, cannot be called a good. A good is the cause of pleasurable states of consciousness. But it would appear strange to claim that joy, happiness, are not goods, and pain, unhappiness, not evils; the terms "good" and "evil" and "worth" refer not only to joy and suffering, but also to desire and will; and no one doubts that happiness is an object of desire, and pain an object of aversion.