Nokea
Most scientists agree that while the scientific method is an invaluable methodological tool, it is not a failsafe method for arriving at objective truth. It is debatable, for example, whether a hypothesis can actually be confirmed by evidence.
When a hypothesis is of the form “All x are y,†it is commonly believed that a piece of evidence that is both x and y confirms the hypothesis. For example, for the hypothesis “All monkeys are hairy,†a particular monkey that is hairy is thought to be a confirming piece of evidence for the hypothesis. A problem arises when one encounters evidence that disproves a hypothesis: while no scientist would argue that one piece of evidence proves a hypothesis, it is possible for one piece of evidence to disprove a hypothesis. To return to the monkey example, one hairless monkey out of one billion hairy monkeys disproves the hypothesis “All monkeys are hairy.†Single pieces of evidence, then, seem to affect a given hypothesis in radically different ways. For this reason, the confirmation of hypotheses is better described as probabilistic.
Hypotheses that can only be proven or disproven based on evidence need to be based on probability because sample sets for such hypotheses are too large. In the monkey example, every single monkey in the history of monkeys would need to be examined before the hypothesis could be proven or disproven. By making confirmation a function of probability, one may make provisional or working conclusions that allow for the possibility of a given hypothesis being disconfirmed in the future. In the monkey case, then, encountering a hairy monkey would slightly raise the probability that “all monkeys are hairy,†while encountering a hairless monkey would slightly decrease the probability that “all monkeys are hairy.†This method of confirming hypotheses is both counterintuitive and controversial, but it allows for evidence to equitably affect hypotheses and it does not require infinite sample sets for confirmation or disconfirmation.
Which of the following is true of hypotheses of the form 'All x are y'?
Correct Answer: D
Rationale: In hypotheses of the form 'All x are y,' the hypothesis is making a claim that all instances of x also fall under y. Therefore, if something is y but not x, it disproves the hypothesis because it contradicts the assertion that all x are y. Choice A is incorrect because something that is neither x nor y doesn't provide evidence against the hypothesis. Choice B is incorrect because if something is both x and y, it actually supports the hypothesis. Choice C is incorrect as something that is x but not y doesn't disprove the hypothesis, as it could still be consistent with the claim that all x are y.