Consequentialism. Consequentialists believe that whether an act is right or wrong depends on its consequences, and in particular, on whether the consequences are good or bad. Roughly, acts that produce good consequences are right and acts that produce bad consequences are wrong. But there are many different consequentialist views.
First, consequentialists can disagree over which consequences are good and which are bad. A great many think that the good is to be understood in terms of things welfare which they often speak of as things like pleasure, happiness, and the satisfaction of desire while the bad is to be understood in terms of things like pain, unhappiness, and unsatisfied desire. These folk are often called 'welfarists' in their account of the good. While most consequentialists give an important place to things like happiness and unhappiness, many think that other things can be good or bad as well. For example, some have thought knowledge, beauty, and the balance of nature are goods to be sought for their own sake. So as not to get too complicated, I will assume that consequentialists are interested only in things like pleasure and pain, happiness and unhappiness, or in a word, welfare.
A second way consequentialists can disagree is about whom the good consequences must be for. Do I only count the consequences for myself, or must I take into account consequences for others? And if I must take into account consequences for others, do I take into account some special group, for example, people in my community, or must I consider all humanity? Some consequentialists think I should take into account the consequences of my actions for all sentient life, that is, on all living things capable of suffering.
Utilitarianism. The most influential form of consequentialism is called 'utilitarianism'. Historically, the leading utilitarians have been the 19th century philosophers Jeremy Bentham and John Stuart Mill. Contemporary utilitarians include J. J. C. Smart, Richard Brandt and Brad Hooker. Actually, like the word 'consequentialism', the word 'utilitarianism' covers a large number of very different views.
Act Utilitarianism. This is the most basic form of utilitarianism. It involves two ideas. First, it declares that an act is right if and only if it maximizes utility for humanity as a whole, or perhaps for all sentient life. Second, it identifies utility with something like welfare. So an act act is right if and only if it produces the most possible welfare for humanity, or perhaps for all sentient life. Act utilitarianism is a maximizing theory. All it cares about is the production of the maximum amount of welfare. This entails two important things. First, it is not important for an act utilitarian how the utility is brought about so long as it is maximized. So, for example, what we would normally consider evil acts might turn out right by act utilitarian lights so long as the consequences are the best possible. Second, act utilitarianism is not concerned with how the good consequences, the welfare, is distributed, so long as the total is maximized. That some people have a great deal and others have little is not important so long as the total is as great as possible. Of course, it is in some sense ideal if everyone can flourish. But in the real world, there are conflicts of interest. Benefiting one individual or group might lead to loss of welfare for another individual or group, and vice versa. When this occurs, someone must win and someone must lose. Act utilitarianism provides a way to decide winners and losers. We do what produces the greatest utility overall. When a number of people are involved, this will often mean that we should do what benefits the majority, but sometimes we should do what benefits a minority. This can be understood from the following charts.
In each case, I assume, for simplicity, that there are two possible acts and three persons involved, P1, P2 and P3. In each case I will assume that the person performing the act is P3. The amount of utility each act produces for each individual is given in the chart. The act with the greatest utility is highlighted in red and the preferences of the majority are highlighted in blue.
Here utilitarianism favors Act 1 and so do all the people involved. This is an ideal situation, when it is possible. P3 can happily perform the act that he prefers knowing that both his fellows, and utilitarianism, will be happy with him.
But it is not always possible to satisfy everyone, or even the agent himself. In this example there is a conflict of interest. P1 and P2 prefer Act 2 while P3 prefers Act 1. Here utilitarianism sides with the majority and says poor P3 must sacrifice her own interest by performing Act 2. She can do this secure in the knowledge that both morality and her fellows appreciate her sacrifice.
But act utilitarianism does not always prescribe what the majority wants. In this example, we have another conflict of interest. The majority, P2 and P3, prefer Act 1. But act utilitarianism favors Act 2. The agent, poor P3, is once alone left with self sacrifice, as well as sacrifice of P2, for the greater good.
For completeness I add one final case. Here the majority prefer Act 2, but the total utility of the acts is the same. So far as act utilitarianism is concerned, the agent, P3, is free to choose which ever she prefers. I suggest she follow her own interest and do Act 2 since in this case she can do so with a clear conscience.
Some Features of Act Utilitarianism.
The Problem of Probabilities. The steps in act utilitarian reasoning just explained leave out once crucial real world dimension of any act utilitarian calculation, the problem that we cannot be sure what the results of our actions will be. This is a simple fact of life. I do something expecting certain things to occur, and something else happens. So we need several extra steps in our picture of act utilitarian reasoning. First, if it is possible, we need to figure out not the actual consequences of our possible actions, but all the possible consequences of our actions. Second, we need to assign probabilities to each possible outcome. So if a given action might have two possible result, A and B, I need to determine, as best I kind the probability that A will occur and the probability that B will occur, once I have acted. Finally, we need a way to bring all this probabilistic information together to decide what to do. That, however, is the subject of a different lecture.