In 2019, thought is much devalued. True, there are more platforms dedicated to it, with more access to each other’s thinking than ever. But this has its downsides, as anyone who has fallen down a Twitter thread (and struggled to climb back out) can attest. There is simply too much of it, a lot of which – ill-informed, hastily constructed and conceived for not altogether noble ends – seems rather pointless. Which is why Mr AC Grayling’s new book The History Of Philosophy, is a timely, thoughtful intervention.

A condensed but comprehensive history lesson, the philosopher and author’s book begins with the ancient philosophers. These first thinkers, knocking around the classical era between the 8th century BC right up to 6th century AD, made points with a rigor contemporary theorists – from trolls and politicians (and those who are difficult to differentiate of the two) – should take pointers in. They also did not feel, refreshingly, that they all the answers, yet still provide much food for thought. Here are five pearls of philosophical wisdom we managed to glean.

Ancient philosophy big gun Socrates would totally own classical antiquity’s equivalent of Question Time. His “Socratic method”, known as “refutation”, asks your opponent to define a concept they’re dead keen on – justice, conscience, Brexit, for instance – in fundamental terms, after which you try and find all of its inconsistencies. Socrates’ point, of course, was more noble than simply trashing other people’s baggy arguments. The conversation ends in indecisiveness, with no definitive answer. As Mr Grayling notes, this was Socrates’ goal. “The wrong or inadequate definitions have been exposed, and something has been learned along the way; namely, that one is ignorant about the true nature of X, whatever this happens to be, and that therefore one needs to think about it more.”

In contrast to the above, the sophists were orators and teachers who, Mr Grayling writes, “taught people how to win arguments, not how to discover truth”. They did so for money, and so did not sit well with philosophical giants such as the aforementioned Socrates and Plato. Yet Mr Grayling is not prepared to simply throw the sophists under the philosophical bus. “The sophists also taught what was required to accompany an ability to be a good public speaker, for there is no use in being eloquent if you have nothing to be eloquent about,” Mr Grayling concludes. As one of their most famous, Protagoras declared: “Art without practice and practice without art are nothing.” So by all means dazzle, but do your homework first.

Philosophy is not the most glamorous pursuit. Socrates gave up worldly goods and personal hygiene to pursue his truth. The first philosopher, Thales, died from thirst and heat stroke. Despite this, the ancient philosophers did not altogether rough it. One of the earliest, Xenophon, recounted a dinner of philosophers, where gentle flower-scented wine was served with golden loaves of bread and a magnificent table laden with cheese and rich honey. Drinking was limited to the point at which everyone can still return home unaided. The lesson: everything in moderation, or at least up to your tipping (over) point.

With his big nose, burly frame and indifference to dress and deodorant, Socrates was not exactly what we in 2019 might consider a thirst trap. Despite being considered something of an outcast, the eccentric philosopher discovered the key to living the good life. This was the life examined and chosen; the “considered life”. A considered life is a life based on knowledge of right and wrong, but Mr Grayling admits that such a philosophy does not allow for us to be human. We all, he notes, chose wrong a lot of the time. But at least we should seriously consider pursuing a considered life.

But what does a considered life look like? Aristotle, the third of the great ancient philosophers after Socrates and Plato, asked: what is the ultimate goal, the highest good? Aristotle argued that this end will be an end in itself, not a means to anything else. Most intelligent sorts agree, he wagered, that this end is happiness or well-being. And how best to achieve well-being? Aristotle suggested that, rather than buying a Himalayan salt lamp and being done with it, the higher life is one of contemplation. In other words, the life of a philosopher. This might read like a humble brag, but Mr Grayling notes it can be applied more widely: that everyone should be afforded the opportunity for leisure and to learn, “enjoying the purest of pleasures: the exercise of our intellects”. So think on that.