The Proofs of God's Existence

On April 15, 1744, I described the principle of this work in the public assembly of the Royal Academy of Sciences of Paris.

At the end of 1744, Professor Euler published his excellent book Methodus inveniendi lineas curvas maximi minimive proprietate gaudentes.

In a supplement to his book, he showed that, in the trajectory of a particle acted on by a central force, the velocity multiplied by the line element of the trajectory is minimized.

This observation gave me great pleasure, as a beautiful application of my principle to the motion of the planets, which is determined by this principle.

From the same principle, I will now try to derive higher and more important truths.

I. Assessment of the Proofs of God’s Existence that are Based on the Marvels of Nature

We find so many arguments for the existence of an all-powerful and all-wise Being.

We don’t need to increase their number.

Rather, we should distill them down to a few solid proofs. We should at least examine the strengths and weaknesses of each argument, to give each one its proper weight; for one can do no greater damage to Truth than to base it on false reasoning.

I will not consider here arguments based on an infinite Being, arguments that seem to prove that an infinitely perfect Being must exist; for that idea is so sublime that, from our finite vantage point, we cannot find a reliable foundation upon which to build reasoned arguments.

I also will not consider the argument that the unanimity of all human beings that God exists is itself a proof of God’s existence, a proof that seemed strong to that Philosopher of ancient Rome (Cicero, Tuscul., I. 13).

Aside from the question of whether all human beings do indeed believe in God’s existence, this argument would be refuted by only a handful of people who thought differently from all other inhabitants of the Earth.

Even those who believe in Him have widely different conceptions of God, which prevents us from exploiting the general agreement about God’s existence as an argument.

Finally, I will not consider the argument for God’s existence from the intelligence that we have within, from the sparks of wisdom and power observed in finite beings, sparks that presumably originate from a source immense and eternal.

All these arguments seem strong to me, but they are not the type I wish to consider here.

Of those who have applied themselves to studying the Universe, several have found traces of the wisdom and power of Him who governs it. The more the field of physics has progressed, the more arguments we find for His existence. However, some have been confused by the character of the Divinity revealed in Nature, while others, almost religiously zealous, have given too much weight to some arguments, considering them proofs when they were not.

Perhaps the rigor of logic may be sometimes relaxed to reach a useful but uncertain conclusion, when it lacks sufficient confirmation. However, the arguments for God’s existence are sufficiently strong and sufficiently many that we can assess them rigorously to determine which arguments are the most certain.

I will not pause to consider the arguments for a supreme Being that the ancients derived from the beauty, order and arrangement of the universe, such as those related by Cicero (Tuscul. I. 28, 29) and Aristotle (De Nat. Deor. II. 37, 38). They knew too little of Nature to be in a position to admire it. Rather, I consider the arguments of a philosopher who made such grand discoveries that he could well judge the truly marvellous in Nature, and whose reasoning was more precise than that of the others.

Newton was moved most of all by arguments derived from the study of the universe, although his deep-thinking mind derived other arguments as well.

He believed (Opticks III. Book. Query 31) that the motion of celestial bodies demonstrated the existence of Him that governs them. Six planets — Mercury, Venus, Earth, Mars, Jupiter and Saturn — revolve about the Sun. All the planets rotate in the same direction in orbits that are more-or-less concentric.

(Nevertheless, there are other bodies, the comets, that follow totally different orbits, moving in all directions and in every region of Heaven.) Newton believed that such uniformity of motion could only result from the will of a supreme Being.

Newton also found strong arguments in less exalted objects. For him, the obvious similarity in the construction of animals, their organization and suitability for their purpose, were convincing arguments for the existence of an all-powerful and all-wise Creator (Theol Astron. de Derham, Theol. Phys. du meme, Theol. des Insectes de Lesser).

A host of physicists following Newton have found arguments for God in astronomical bodies, in insects, in plants and even in water (Theol. de l’Eau de Fabricius).

Let us not disguise the weakness of these arguments; indeed, to better understand the abuse which some have made of proofs of God’s existence, let us critique even arguments as strong as those of Newton.