Surety brings ruin

‘Surety brings ruin’ is one of three maxims inscribed prominently on the Temple to Apollo in Dephi.

This maxim has two interpretations. The literal translation is “a pledge, then calamity”, where the Greek word for pledge refers to property or money put up as collateral on a loan, or to bail someone out of jail. It could be translated as ‘a pledge is folly’ or more simply, ‘don’t over-commit yourself’. This meaning, whilst very good advice, is rather prosaic especially compared to the profundity and wisdom of the other two Delphic maxims, Know Thyself and Nothing in Excess.

A more compelling interpretation of ‘surety brings ruin’ is that given by Diogenes Laertius in his Life of Pyrrho. Diogenes thought of it as a sort of scepticism, in other words it is saying, certainty is foolish.

Don’t be so sure of yourself

It is advisable to not be so sure, everyone is wrong sometimes, and the problem is we don’t know when we are. The wise person knows how little they know. Additionally, a wise person also knows that what they think they know is at best an approximation of the truth. 

The best we have are ‘working’ truths. The truths we work with tend to evolve as we learn more. Obviously, it is hard to progress without being able to assume that certain knowledge is correct, but this must always be treated with prudence. 

In the past surety, or certainty, has resulted in a lot of ruin. Take asbestos, DDT and CFCs for example; people were sure they would be fine but they weren’t. There were masterminds in England who were sure it would be fine to feed cows, which are herbivores, ground up meal that contained infected meat. The resulting ruin from the outbreak of BSE (or Mad Cow’s Disease) included over four million head of cattle being slaughtered in an effort to contain the outbreak, and 177 people died after contracting vCJD (the human variant of BSE) through eating infected beef. In the 1920s it was decided that it was fine to add lead to petrol, even though lead poisoning had been known for centuries. By the 1960s it was apparent that it wasn’t fine but it still took another 40 years for it to be banned. And the inventor of leaded petrol, Thomas Midgley’s next trick was to invent the aforementioned CFCs.

People are often certain about beliefs e.g. fundamentalist Christians and Muslims. However, a belief, by definition, is unproven. If you want to believe something that’s fine but never judge, discriminate or harm people who don’t believe the same thing. 

It is important to remember that humans are not perfect, we are fallible. Nietzsche said we aren’t finished yet. Nietzsche also realised that knowledge is from a “perspective”. And different people have different perspectives meaning they have different knowledge and different working truths.


One of the most destructive aspects of human nature that besets most people to some degree, is insecurity. Insecurity is a type of fear that develops through a combination of our personality, our circumstances, and our past experiences. It is the opposite of surety and certainty.

In many cases, insecurity comes from comparing ourselves to others. As self-conscious and social beings, we can feel insecure about our faults, failings and shortcomings, especially as they relate to others. We can have self-doubt, feelings of unworthiness and anxiety about the way others perceive us. The fact that we are highly social animals drives these insecurities; feelings and emotions guide our sociability. The evolutionary benefit for this is that individual humans survive better in groups. Some of our deepest-set needs are to belong, fit in, and be worthy of others’ consideration and respect. We are anxious to fill these needs.

Humans have many strategies, both functional and dysfunctional, to cope with insecurity. Affluence, greed and exploitation are, essentially, types of coping mechanisms. Another is arrogance, which makes one act and feel too sure of themselves.


Thomas Merton once wrote a letter to Rachel Carson about heedless technological progress and said humans are “…buried under our pitiful and superficial optimism about ourselves and our affluent society.”

Humanity on the whole seems to have a type of arrogance that comes from the ‘myth of our specialness’ ingrained in our collective psyche. Too many people think that since we are the most intelligent, most dominant life-form on earth, we can do what we like. Arrogance leads to entitlement, self-indulgence and thoughtlessness, even when that means mass extinctions and the ruination of nature. It is said that if humans suddenly ceased to exist, all the other life on earth would sigh with relief. Arrogance is related to a ‘fixed’ mindset. It says, “I am right, and I will continue to prove it”. It is a supreme vanity. 

The vice of arrogance is the opposite of the virtue of justice because it says that human individuals can have more than their fair share, taking more than they need and exploiting and dominating our shared planet in unsustainable ways.


Being too certain is too extreme. Clearly some humility and prudence is called for.

The opposite of a Fixed mindset is a ‘Growth’ mindset which says ‘I am not the finished me. I can be better.’ By pursuing excellence (virtue) people can grow, however excellence needs to be tempered with what Aristotle called ‘Phronesis’, a word which could be translated as prudence or ‘practical wisdom’. Practical wisdom is the ability to know and do the right thing, but also in the right amount, at the right time, for the right reason. You might say that practical wisdom is synonymous with being reasonable.

Being reasonable is the opposite of ‘surety’.

Further Reading

The three maxims inscribed on the forecourt of the Temple to Apollo at Delphi are:

Know thyself (Greek: Γνῶθι σεαυτόν, gnōthi seautón).

Nothing in excess (Greek: μηδὲν ἄγαν, mēdén ágan)

Surety brings ruin (Greek: Ἐγγύα πάρα δ, engýa pára d’atē)