Christiaan Huygens

The phenomena of nature are not arbitrary, but follow fixed laws.

The pursuit of truth requires an open mind and a willingness to challenge established beliefs.

The universe is a vast machine, operating according to precise mathematical rules.

The true scientist is one who is not afraid to admit ignorance.

The search for knowledge is an endless journey.

The wonders of the universe are beyond human comprehension, yet we strive to understand them.

I believe that we do not know anything for certain, but everything probably.

It is impossible to explain the admirable economy of the solar system by the sole cause of gravity.

Light consists in the motion of a certain kind of matter.

There is no doubt that light consists in the motion of a certain substance... For if one examines its production, one sees that here on Earth it is chiefly fire and flame which engender it, both of which contain bodies which are in rapid motion.

It is inconceivable to doubt that light consists in the motion of some sort of matter.

Sound spreads through the air by a motion which is passed on from one particle to another.

In true philosophy... the causes of all natural phenomena are conceived by mechanical reasons.

One finds in this subject a kind of demonstration which does not carry with it so high a degree of certainty as that employed in geometry; and which differs distinctly from the method employed by geometers in that they prove their propositions by well-established and incontrovertible principles, while here principles are verified by the conclusions which are drawn from them.

The apparent magnitude of the fixed stars is not a measure of their distance.

The planets are not points, but worlds, comparable to our own.

It's a most beautiful and delightful sight to behold the body of the Moon.

Saturn is surrounded by a thin, flat ring, nowhere touching, inclined to the ecliptic.

I have discovered a new and most singular planet... armed with two handles.

The nature of light is not yet known to us.