True Friendship Requires Knowing Someone’s Character — Why Surface Knowledge Falls Short

Why Does Aristotle Demand Complete Character Knowledge?

In Aristotle’s theory of friendship, complete character knowledge is a necessary condition for the highest form of friendship. Both friends must know the other’s entire character so that their admiration and affection rest on a solid foundation.

This demand is closely tied to the concept of the friend as an “other self.” Cooper (1977) argues: through a friend, you gain an objective view of yourself. That presupposes knowing your friend in their entirety — otherwise they reflect only a distorted self-image.

Two Types of Knowledge Gaps

The problem of incomplete character knowledge manifests in two interconnected difficulties.

1. Incomplete knowledge.People can withhold information about themselves — sometimes deliberately, often unconsciously. Selective self-presentation enables a kind of preemptive censorship: you choose when, how, and for how long you communicate, showing only certain facets.

2. Ignorance of your own ignorance.Even more problematic: both sides are unaware of the gaps in their knowledge. You believe you know your friend completely — but you don’t. Even if the hidden traits were virtuous, the withholding itself is problematic — it reveals a lack of practical wisdom (phronesis).

Online Friendship and Self-Censorship

The problem of incomplete character knowledge is especially visible in the virtual world. Cocking and Matthews (2000) argued that the possibilities of selective self-presentation online make close friendship in purely virtual contexts psychologically harder.

Online, you choose when to reply, which photo to show, which story to tell. This controlled communication prevents the chance encounters with someone’s full character — the moments under stress, in failure, in the kitchen.

Briggle (2008) disagreed: the slower pace of online communication could even lead to deeper exchange. The truth likely lies in between: online friendships slow the process of character knowledge but do not fundamentally prevent it.

Heraclitus in the Kitchen

In Parts of Animals, Aristotle recounts an anecdote: visitors hesitate to seek out Heraclitus in his kitchen. He tells them: “Enter, for here too there are gods.” Even seemingly lowly topics and situations deserve philosophical attention.

By analogy, the “lowly” sides of a person also deserve attention, because only through them does a complete picture emerge. Sharing life in the real world forces this confrontation: you encounter each other in unexpected situations, under stress, in everyday and mundane moments. That is precisely what makes offline friendships richer than purely digital relationships.

Is Complete Knowledge Even Possible?

The honest answer: rarely. Even in offline friendships, people conceal weaknesses. The rules of friendship actually prescribe not disclosing everything ruthlessly. And every friendship begins with limited knowledge and deepens only over time.

Modern conceptions of friendship place less emphasis on recognizing virtue and more on emotional closeness, trust, and reciprocity. Aristotle’s demand nonetheless remains valuable — as a guiding principle: the more you know about a friend, the more solid the relationship. And the more honest you are, the deeper the friendship quality can become.

Frequently Asked Questions

Do you need to know a friend completely?

In Aristotle’s ideal, yes — virtue friendship presupposes that both people know the other’s entire character: strengths and weaknesses. In practice, this is an ideal rarely fully achieved. But the direction is right: the more you know about a friend, the more solid the relationship.

Can you find real friends online?

It is harder than offline. Online communication enables selective self-presentation: you choose when and how to communicate and show only certain facets. This makes the complete character knowledge needed for deep friendship more difficult — but it does not prevent it altogether; it slows the process.

What are the two types of knowledge gaps?

First, incomplete knowledge: information is withheld, consciously or unconsciously. Second — and more problematic — ignorance of your own ignorance: you believe you know your friend completely, even though essential aspects are missing.

How do you learn a friend’s character?

By living through unexpected situations together: under stress, in failure, in everyday and mundane moments. This forces a confrontation with the full spectrum of character — not just the sides that are deliberately shown.