A Plea for Persuasion
Jane Austen’s sixth and final novel is entitled Persuasion. There is a reason it is so entitled—it deals with the role of persuasion in human life (as exemplified in Anne Eliot being persuaded against her better judgment not to marry Captain Wentworth). But we might see the whole sequence of her novels as occupied with the topic of persuasion in one way or another. In any case, she clearly believes that persuasion is central to human life, for good or ill. It is not hard to see why: persuasion is heavily implicated in personal relations (courtship, seduction), in politics and diplomacy, in business and finance, in law, in science, in philosophy, in scholarly discourse generally, and in any form of leadership. To the most persuasive go the spoils, we might say. Accordingly, psychology has studied the workings of persuasion, exploring the principles whereby persuasion operates (the role of authority, conformity, reciprocity, commitment, liking, etc.).  But philosophy has not been much concerned with the topic: the philosophy of language has little to say about it, and epistemology has not found a place for persuasion as a source of both knowledge and error. Plato was certainly interested in it because of its place in the armory of the sophists (there is good persuasion and bad persuasion), but recent philosophy has been silent on the subject. Here I will make some remarks intended to bring persuasion into the conversation. Given its centrality to human life, it might be useful to get a bit clearer about it.
Consider speech act theory. We are told that there are several kinds of speech act, each irreducible to the others—assertion, command, question, performative, etc. Wittgenstein took this plurality to the extreme, contending that there are “countless” ways of using language with nothing significant in common. The idea that persuasion might be the common thread has not been mooted. But note that, while one can only assert that and order to, one can both persuade that and persuade to. That is, persuasion can aim at both belief and action, while assertion aims only at belief and command only at action. The OED has two definitions for “persuade”: “cause to do something through reasoning or argument” and “cause to believe something”. So persuasion is a genus with two species, corresponding to assertion and command—inducing the other to believe or to act. Whether these can be unified is an interesting question: might belief formation be a type of action, or action a result of a specific type of belief (say, the belief that this action is best all things considered)?  Maybe all persuasion is persuasion-that, with practical belief the kind aimed at by command. In any case, persuasion covers both types of speech act; so we need not accept irreducible plurality. Questioning might then take its place as persuading the other to provide information (a special case of command perhaps)—“I wonder whether you would be so kind as to tell me the time”. This seems like an attractive all-encompassing conception: speech as persuasion. If it is objected that not all talk is talking-into (or out of), because speakers are not always offering arguments, we can reply that persuasion need not always be explicit—there is also implicit persuasion. All speech acts are implicitly (or explicitly) argument-like because they offer reasons for the hearer to respond in a certain way: assertion involves inviting the hearer to reason from the speaker’s making an utterance to the likelihood of its being true, and command involves getting the hearer to recognize that the speaker is in a position to enforce what he commands (or would be displeased if ignored).  The hearer is always reasoning from premises about what the speaker has said and responding accordingly. So even a simple speech act is tacitly argument-like: if I just shout, “Help!” I am trying to persuade you to come to my assistance by reasoning about why I would make that noise. In a benign sense, I am manipulating you—trying to get you to do (or think) what I want. Even when a cat meows to go out she is trying to persuade you to open the door for her. We have a strong interest in getting people to act so as to promote our desires; speech is a way of making this happen, and so persuasion is central to it. In talking we are always talking people into believing and doing (compare: all seeing is seeing-as). Thus persuasion is the general type of all speech acts. 
Conceptually, persuasion is necessarily intentional: when we persuade we do so intentionally. This means that we can never try to persuade someone of what we know he will not do or believe: we don’t set out to persuade the unpersuadable. You may try to entertain or embarrass someone by talking to him even if you know he won’t be convinced, but you won’t be trying to persuade him of what you are saying. You only try to persuade people you regard as (minimally) rational. So the practice of persuasion presupposes an assumption of rationality; it takes place against a background of respect for the other as a rational agent. When this is lacking persuasion might be replaced by brute force—making the other to do what you want him to (rightly or wrongly). Thus you don’t try to persuade toddlers to do what you want them to; you simply impose your will on them. Persuasion occurs within what Kant would call the kingdom of ends—respect for others as autonomous rational agents. Crucially, persuasion calls upon consent (unlike the brute exercise of power): you are trying to get someone to agree with what you are saying. And they may not: they may reject your arguments, refusing to shape their beliefs or actions as you suggest. The consent may be of many kinds, from sexual to political, scientific to economic. Advertising is trying to persuade people to buy things, but people may not consent to spending their money as you wish them to. It takes two to persuade successfully: the would-be persuader and the targeted consenter. The persuader is trying to secure the free assent of the consenter. There are many possible ways of doing this, ranging from outright psychological manipulation to the purest rational argument; but there is no skipping the obligation to secure assent if persuasion is the name of the game. Thus persuasion is always preferable to coercion and should not be regarded as a special case of coercion. Never coerce where you can persuade.
Persuasion may be a step up from coercion, but it is still inherently problematic: this is what so exercised Plato, as well as Jane Austen. For any good act of persuasion there are many bad acts. There is education, but also propaganda; there is logical reasoning, but also bullshit and manipulation. Moreover, it is not always easy to tell one from the other (they don’t come in different color ink). The credulity of human beings is as obvious as their educability. People can be persuaded of the most arrant nonsense if it suits them to be so persuaded. The con man can be as convincing as the wisest sage. The trick is to be persuadable just when one ought to be persuadable, but that is no easy task. Memes and fakery lurk around every corner. The Internet is a cesspool of toxic phony persuasion. It’s enough to make you want to give up on persuading anyone of anything—abandoning the very idea of persuasion! But no, we must persist in sorting out the wheat from the chaff. I am laboring the obvious, but we must always be aware of the potential evil inherent in persuasion, always on the lookout for its pernicious forms and manifestations. Just think of human history without pernicious persuasion!
Logically, persuasion is a four-place relation: x persuades y of p by means of m. We can allow for reflexive persuasion, as when you persuade yourself of something, but persuasion is always directed at some object. The value of p might be a proposition or an action, depending on whether the speech act is assertive or imperative. There must always be a means m that may vary while keeping p constant: you may try different m to secure the same p. This too is essential to persuasion: it is not like logical proof, but a matter of individual psychology (Euclid was more of a deducer than a persuader). Persuading is like teaching someone to dance: there are many ways to do it so long as you get them dancing (but please, no coercion!). What we must not do is persuade by lying (except in very special cases): in the general case, the recipient assumes that the means you are employing does not involve outright falsehood—that is part of the pact of persuasion. I am prepared to be persuaded by you, but only if you tell me the truth. Truthfulness and persuasion go together. So persuasion is quite a complex operation, not one available to organisms generally. Add this to the condition that persuasion is always intentional and we get the result that an agent can persuade only if she possesses reflective knowledge of the means and ends integral to a given persuasive act (this includes the meowing cat). And you can only be good at instantiating this relation if you are skilled in the arts of persuasion; indeed, you do well to learn those arts as you would any complex skill. You should take Persuasion 101 and possibly get an advanced degree in it (if you want to be a diplomat, say). Practice your persuasive skills daily (the good kind, of course).
We should not neglect the use of the concept of persuasion in “I am persuaded that p”: what kind of state of mind does this describe? This state could come about otherwise than by some other person persuading you; it could issue from the facts themselves (and we do sometimes speak of facts as persuasive, usually in relation to a theory). This locution appears to suggest something stronger, more potent, than mere belief: I don’t just believe that p; I’m prepared to act on it. Thus it edges towards the conative—it is motivational. If someone announces that she is persuaded that eating meat is wrong, we expect abstinence from meat eating (note the conceptual connection between persuasion and doing). Thus the concept appears to straddle belief and desire, i.e. it suggests motivating beliefs. This seems like the right notion to employ in moral psychology: we don’t merely believe certain moral principles; we find them persuasive. So the concept of persuasion seems to have a role in moral motivation: to be persuaded that eating meat is wrong you have to take yourself to have very good reasons for not eating meat. You don’t just think it’s wrong; you are persuaded it’s wrong. That is your persuasion, your conviction, and your commitment. When Anne Eliot was persuaded not to marry Captain Wentworth she acted on it; it wasn’t just a state of her cognitive apparatus. Jane Austen’s novel has a title that denotes both a verbal act and a state of mind: the act of persuading and the state of being of a certain persuasion. We could say that though Miss Eliot was persuaded at age 19 not to marry Captain Wentworth, it was never her persuasion that she should not marry him—which is why she did marry him seven years later. It was not her deep conviction and she regretted her earlier decision. You can be persuaded to do something without it being your persuasion.
A cluster of concepts has captured the attention of philosophers: knowledge, belief, certainty, intention, assertion, reason, justification, testimony, and argument. I suggest we add the concept of persuasion to this list. 
 We have become accustomed to speaking of speech as communication, but that term is loaded, connoting the transfer of something from speaker to hearer (the OED has “share or exchange information or ideas”). But the persuasion conception suggests rather the idea of influence: speaking is causing the hearer to react in a certain way, not giving him something. The speaker is exercising a certain power over the hearer not conveying something precious.
 Here is an interesting question for the new field of persuasion studies: how do performatives persuade? Not by stating language-independent facts but by the very issuing of them. I am persuaded that you have promised to meet me precisely because I just heard you utter the sentence “I promise to meet you”. This type of persuasion is very effective because the speaker doesn’t need to rely on the cooperation of outside facts—the speech act alone suffices to make it so. Hence performatives are uniquely persuasive (possible paper title, “Persuasive Performatives”).