Is–ought problem:

Conceptual Fallacy

Definition	Example
When there is an inference that, because something is a particular way, it ought to be that way.	Nearly all humans wear clothing in public, so it is immoral not to.
Also known as: isolated ought
Notes
Any “ought” will need to be accompanied by an “if” for it to have any meaning. For example, you can tell your friend he ought to hurry if he wants to catch the bus, but an “ought” isolated from an “if” carries no meaning. Even a statement such as “You ought to listen to your parents” carries an implicit “if”. If you do as they say, you’ll avoid undesirable consequences. Another example is in the context of a game of chess. You ought not cheat in chess because it is socially unacceptable; i.e., if you want to maintain social respect. Even religious-based moral “oughts” contain implicit “if”s as in “You ought not lie if you want to please God and avoid eternal torment.” “Ought”s cannot be divorced from “if”s.   “In every system of morality, which I have hitherto met with, I have always remark’d, that the author proceeds for some time in the ordinary ways of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when all of a sudden I am surpriz’d to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, ’tis necessary that it shou’d be observ’d and explain’d; and at the same time that a reason should be given; for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it.” David Hume in Treatise of Human Nature

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Case Study One

Ayn Rand argued that one ought to act in a way consistent with one’s own rational self-interests. The implicit “if” is presumably “if you want to live a long and happy life.” Yet it is never explained why a life of altruism cannot also lead to a long and happy life, and why altruism ought to be replaced by a more egoistic existence.

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Case Study Two

Just as the existence of an “is” does not demand an “ought”, neither does the existence of an “is” demand an “ought not” in the form of a human right that “ought not” be violated. The existence of an economy healthy enough to provide universal health care, or that does currently provide universal health care, does not mean such universal health care is a human right or moral obligation. Any objective human right must be defended with arguments that do not simply invoke what currently exists.

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^{Keep in mind that a fallacious argument does not entail an erroneous position.}

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