Torbjörn Tännsjö

Should we change the human genome? The most general arguments against changing the human genome are here in focus. Distinctions are made between positive and negative gene therapy, between germ-line and somatic therapy, and between therapy where the intention is to benefit a particular individual (a future child) and where the intention is to benefit the human gene-pool.Some standard arguments against gene-therapy are dismissed. Negative somatic therapy is not controversial. Even negative, germ-line therapy is endorsed, if the intention is to cure a certain individual (a future child). In rare cases, positive therapy on somatic cells may be warranted. Germ-line therapy may become a valuable method of preventing harm, through genetic vaccination. If safe methods evolve, it is harmless (though vain), to try to achieve more ambitious goals. Prospective parents should not be prevented from exercising this harmless kind of parental authority.

I conclude that the explanatory view of consequences is a fruitful one.This view accounts for our common sense view that actions are, in some sense, ‘sufficient’ for their consequences. It shows in a concrete and illuminating manner that we are or may be responsible for a vast number of events no matter how ‘innocently’ our actions may be described. It allows for the fact that individuals lack responsibility for consequences of collective actions, thereby explaining a generally felt ‘double effect’ built into our social morality. It brings into light and explains the fact that some degree of determinism seems to be presupposed if people are ever morally responsible for any events whatsoever. Finally, the explanatory view of consequences yields precise and attractive interpretations of the open and the closed views of responsibility

Derek Parfit has famously pointed out that ‘total’ utilitarian views, such as classical hedonistic utilitarianism, lead to the conclusion that, to each population of quite happy persons there corresponds a more extensive population with people living lives just worth living, which is better. In particular, for any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better, even though its members have lives that are barely worth living. This world is better if the sum total of well-being is great enough, and it is great enough if only enough sentient beings inhabit it. This conclusion has been considered by Parfit and others to be ‘repugnant’.

The repugnant conclusion is acceptable from the point of view of total utilitarianism. Total utilitarians do not seem to be bothered with it. They feel that it is in no way repugnant. To me, a hard-nosed total utilitarian, this settles the case. However, if, sometimes, I doubt that total utilitarianism has the final say in ethics, and tend to think that there may be something to some objection to it or another, it is the objection to it brought forward from egalitarian thought that first comes to mind. But if my argument in this article is correct, then it is clear that the repugnant conclusion should be equally acceptable to egalitarians of various different bents as it is to total utilitarians

When and why is it right to kill? When and why is it wrong? Torbjörn Tännsjö examines three theories on the ethics of killing in this book: deontology, a libertarian moral rights theory, and utilitarianism. The implications of each theory are worked out for different kinds of killing: trolley-cases, murder, capital punishment, suicide, assisted death, abortion, killing in war, and the killing of animals. These implications are confronted with our intuitions in relation to them, and our moral intuitions are examined in turn. Only those intuitions that survive an understanding of how we have come to hold them are seen as 'considered' intuitions. The idea is that the theory that can best explain the content of our considered intuitions gains inductive support from them. We must transcend our narrow cultural horizons and avoid certain cognitive mistakes in order to hold considered intuitions. In this volume, suitable for courses in ethics and applied ethics, Tännsjö argues that in the final analysis utilitarianism can best account for, and explain, our considered intuitions about all these kinds of killing.

A simple hedonistic theory allowing for interpersonal comparisons of happiness is taken for granted in this article. The hedonistic theory is used to compare utilitarianism, urging us to maximize the sum total of happiness, with prioritarianism, urging us to maximize a sum total of weighed happiness. It is argued with reference to a few thought experiments that utilitarianism is, intuitively speaking, more plausible than prioritarianism. The problem with prioritarianism surfaces when prudence and morality come apart

The expressivist theory of truth (TETT) is stated and defended. According to TETT, to state such things as that it is true that snow is white is to express one's assent to the proposition that snow is white. In contexts where we refer to propositions with the aid of definite descriptions (“What Peter said”) or quantify over them (“Everything Peter says”), in order to say that they are “true”, the word “true” is essential, however. But it does not stand for any genuine property. According to TETT, as here understood, it expresses our readiness or willingness to assent to these propositions. It is argued that TETT, even if still more of a reseach program than a full‐fledged theory, means an improvement over more elaborate minimalist theories of truth put forward by Crispin Wright and Paul Horwich.