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  • Print publication year: 2012
  • Online publication date: June 2012

5 - Identifying and evaluating arguments: logic and morality

from Part I - Bioethics and Ethics



In reading this chapter you will:

acquire some logical terminology;

learn about deduction and induction;

consider the difference between deductive validity and inductive strength;

learn how to evaluate arguments;

discover how to analyse arguments and set them out ‘logic-book style’;

learn about a few important fallacies;

reflect on the importance of the principle of charity.

Argument is the philosophical method. This is why philosophers study logic, the discipline that tells us how to distinguish good arguments from bad. There are many problems that can be approached only by using logic. Consider, for example, the following sentence:

Therapeutic cloning is morally acceptable.

Therapeutic cloning (as we’ll see in Chapter 7) is cloning for the purposes of conducting research on, or harvesting stem cells from, the resulting embryo. Some of us will believe sentence (1) is true. Others will believe it is false. We can’t both be right. Which of us is right is not the sort of question the truth of which can be determined by observation or experiment. This can be decided only by engaging in argument.

Chalmers, A. F. 2000 What is this Thing Called Science? Maidenhead, UK Open University Press
Popper, K. 1991 The Poverty of Historicism New York Routledge
Quine, W. V. 1964 Word and Object Cambridge, MA MIT Press