To what extent do our arguments reflect our character and moral principles?
If a mathematician made a mistake in formulating an equation, nobody would attribute his error to some kind of character flaw. The more abstract or theoretical a subject, the less any arguments about it are thought to reveal anything about the persons expressing them, other than their reasoning powers or knowledge.
So it’s clear that “we are not our arguments” when purely technical concepts are concerned.
However, if the subject in question relates to, say, our policy preferences or values, an argument about it might well reveal something more than just intellectual ability: For example, if someone today espoused the notion that slavery would be a sensible approach to ensure economic prosperity, such a position could be thought to reveal the character or moral quality of its proponent. For this reason, it sometimes seems nonsensical to say that while one abhors and condemns certain behaviors or views, such disapproval concerns only the behaviors and views in question, but not at all the people who embrace them, as if the two were wholly disconnected. An example to illustrate the potential absurdity of that position could be “I detest Nazism but have nothing against Nazis”.
Of course such a position may not always be absurd: People may be indoctrinated, brainwashed, manipulated, deceived, pressured, compelled and even forced to adopt behaviors and positions that perhaps they wouldn’t otherwise favor.
Now, even if certain views may sometimes be thought to partially reflect differences in our character and temperament, in fact in many situations that’s not at all the case, for the simple reason that we all largely share the same human nature. We should bear that in mind when entangled in political discussions, for instance. We should start with identifying our common ground, our common objectives. For example, we could agree that the ultimate goal around a given set of policies is to ensure that everyone is given an equal opportunity to thrive and flourish as a human being. If all sides agreed on that, then it would become evident that accusing an opponent of evil intentions or questionable sentiments just because he disagrees with us on how best to accomplish that goal would be senseless. Once we realize that our ultimate goals are not really that dissimilar, the discussion should rather be considered technical as opposed to moral; similar to a bunch of mathematicians discussing how to go about proving or disproving a mathematical conjecture: different approaches would indicate nothing about the morals of their proponents. Political discussions would be far less toxic if we kept that in mind.