How the Greeks Knew the Earth was a Sphere


‘As long ago as 340 BC the Greek philosopher Aristotle, in his book On the Heavens,
was able to put forward two good arguments for believing that the earth was a round sphere rather than a Hat plate. First, he realized that eclipses of the moon were caused by the earth coming between the sun and the moon. The earth’s shadow on the moon was always round, which would be true only if the earth was spherical. If the earth had been a flat disk, the shadow would have been elongated and elliptical, unless the eclipse always occurred at a time when the sun was directly under the center of the disk. Second, the Greeks knew from their travels that the North Star appeared lower in the sky when viewed in the south than it did in more northerly regions. (Since the North Star lies over the North Pole, it appears to be directly above an observer at the North Pole, but to someone looking from the equator, it appears to lie just at the horizon. From the difference in the apparent position of the North Star in Egypt and Greece, Aristotle even quoted an estimate that the distance around the earth was 400,000 stadia. It is not known exactly what length a stadium was, but it may have been about 200 yards, which would make Aristotle’s estimate about twice the currently accepted figure. The Greeks even had a third argument that the earth must be round, for why else does one first see the sails of a ship coming over the horizon, and only later see the hull?’

– Hawking. S. (1998) A Brief History of Time New York, United States: Bantam Books p. 2

Incomplete Intelligibility


‘In the language which is spoken when one expresses oneself, there lies an average intelligibility; and in accordance with this intelligibility the discourse which is communicated can be understood to a considerable extent, even if the hearer does not bring himself into such a kind of Being towards what the discourse is about as to have a primordial understanding of it. We do not so much understand the entities which are talked about; we already are listening only to what is said-in-the-talk as such. What is said-in-the-talk gets understood; but what the talk is about is understood only approximately and superficially. We have the same thing in view, because it is in the same averageness that we have a common understanding of what is said.’

Being and Time by Martin Heidegger, tr. John Macquerrie and Edward Robinson, Oxford: Blackwell Publishers Ltd., 1962, I.5, §35 (H.167), p. 212

On Freedom from Pain


Chorus of Theban Elders: ‘Therefore, while our eyes wait to see the destined final day, we must call no one happy who is of mortal race, until he hath crossed life’s border, free from pain.’

– Sophocles, Oedipus Rex


Taken from Oedipus the King, lines 1529-1530; as published in The Tragedies of Sophocles (1917), translated by Richard Claverhouse Jebb.

The Human Race


The thinking ape
200,000 years ago

Our species, Homo sapiens, is ridiculously young. We have only existed for a fifth of a million years. In that time we have expanded from our African birthplace to reach every continent, and even outer space. Our activities have precipitated the sixth mass extinction and unleashed the fastest episode of climate change in Earth’s history. Yet we are also the only species that has ever managed to piece together the history of Earth.

See other: History of Life

Conversations: Civilization


Helena
It is important to realize that the distinction between science and religion is not a matter of excluding our ethical intuitions and spiritual experiences from our conversation about the world; it is a matter of our being honest about what we can reasonably conclude on their basis.

Xanthippe
However, there are good reasons to believe that people like Jesus and the Buddha weren’t talking nonsense when they spoke about our capacity as human beings to transform our lives in rare and beautiful ways.

Sappho
But any genuine exploration of ethics or the contemplative life demands the same standards of reasonableness and self-criticism that animate all intellectual discourse. Continue reading

Conversations: The Preposterous


Helena
Clearly, it is time we all learned to meet our emotional needs without embracing the preposterous. We must find ways to invoke the power of ritual and to mark those transitions in every human life that demand profundity—birth, marriage, death—without lying to ourselves about the nature of reality.

Galene
What does that mean in practice?

Sappho
I feel we should recognise that, for instance, the practice of raising children to believe that they are Christian, Muslim, or Jewish should be recognised as the ludicrous obscenity that it is. And only then will we stand a chance of healing the deepest and most dangerous fractures in our world.

Galene
That’s all very well and good, but I have no doubt that the acceptance—so to speak—of Christ coincided with some very positive changes in some people’s lives. Perhaps they now love other people in a way that they never imagined possible. They may even experience feelings of bliss while praying—say. Continue reading

The First Hominids


The road to humanity
13-7 million years ago

The first apes appeared in Africa around 25 million years ago. Then at some point, the group split into the ancestors of modern humans and the ancestors of modern apes. It is hard to say exactly when, but thanks to modern genetics and a host of fossil discoveries, we have a rough idea. The oldest known hominid was Sahelanthropus tchadensis, which lived about 7 million years ago.

See other: History of Life

Conversations: Eradicating Religion


Helena
I would argue that one of the greatest challenges facing civilization in the twenty first century is for human beings to learn to speak about their deepest personal concerns—about ethics, spiritual experience, and the inevitability of human suffering—in ways that are not flagrantly irrational.

Sappho
Absolutely. We desperately need a public discourse that encourages critical thinking and intellectual honesty! Unfortunately, it is probably true to say that nothing stands in the way of this project more than the respect we accord religious faith.

Zoe
Surely, you would be the first to admit that the prospects for eradicating religion in our time do not seem good? Continue reading