ARISTOTLE AND THE SCIENCE OF LOGIC

             Aristotle founded the science or logic. Among Aristotle's works on logic was Of Sophistical Refutations, which dealt with arguments that appear sound but that for one reason or another are not.

             Logic is the study of argument. Every argument consists of two basic elements: premises and a conclusion. This is what distinguishes arguments from nonarguments.

             Not all arguments display their structure simply. As ordinarily expressed, arguments are encumbered with excessive verbiage and irrelevance and often rest on hidden or unexpressed assumptions. In order to judge the soundness of arguments one must learn how to recognize and eliminate verbiage and how to identify hidden and unstated assumptions.

             In deductive arguments, the premises contain all the information necessary for the conclusion; in inductive arguments, the conclusion goes beyond the data contained in the premises. Thus, even in the best inductive arguments, the conclusion is only probable, whereas the conclusion in a deductively valid argument follows with necessity.

             An argument has three characteristics on which it may he evaluated. The first is the truth or falsity of the premises. The second is the validity or invalidity of the reasoning from the premises. The third is the argument's soundness (which exists whenever the premises are true and the reasoning valid) or unsoundness (which exists if truth and/or validity is lacking).

Something may indeed follow from something else without it necessarily being true. ether or not a conclusion is true will depend on whether the premises it follows from are true. In short, a conclusion may be valid (i.e. may follow from a  premise) but be false.