| Several points.
The quality of one opinion has no bearing on the validity of another. Assuming we take certain criteria for assessing opinions (for example, coherence/logical consistency or evidence), then an opposing opinion does not take into account the basic validity of an argument. If you have two views on an issue, making one wrong does not make the other right (if they are genuinely competing views, then making one right does make the other wrong, but this is very rare when dealing with reality). Only when two arguments are valid can they be competition to one another.
Any argument has three basic elements: premises, conclusion and a relationship between the two. A logical critique can address any (or all) of these elements. Once again, this has absolutely nothing to do with any alternative explanations or positions. The first thing I notice with people who are not trained in debate (or philosophical writing) is that they struggle to explicate these elements properly, meaning that their argument appears confused and the reader has to guess at elements of it. Experienced writers do this as well.
There are three basic forms of premise: assertion, hypothesis and value (my terms). An assertion is something that is claimed to be true. It is valid if it is a conclusion of a valid argument. A hypothesis is a statement about reality, which can be tested. If it is consistent with reality, then it is valid; if it is not, then it is not. A value is a basic belief that usually cannot be argued (akin to metaphysical statements in philosophy; but generally slightly broader). Most arguments contain all three types of premise in one form or another. Logos, pathos and ethos are techniques usually used to substantiate premises.
Relationships can also be logical or empirical. They come in four forms as well: causal, correlational, incidental, or co-determined (once again, my terms). Causal means that the premises make the conclusion come to happen. Correlational means that the premises and the conclusion happen together, but not causally. Incidental means that any link between the premises and conclusions is a product of chance. Co-determined means that the premises and the conclusion are both products of some other factors not present in the argument. |