subtile

Recent scientific discoveries have conferred upon man new powers of investigation, whereby nature has been made to reveal secrets so subtile that they never had been dreamt of before in philosophy.

From Scientific American ● Jan. 13, 2013

At Paris the Universe is seen, compos’d of Vortices of subtile Matter; but nothing like it is seen in London.

From "The Invention of Science" by David Wootton

Not by any altruistic agency we may be certain, as we watch the selfish, irritable little beings, but by subtile scent, or as with the vultures, by the jealous watching of each other's actions.

From Jungle Peace by William Beebe

We find doctors in the first ages speaking to us of God and the soul as material substances, more subtile indeed than ordinary bodies.

From Ecce Homo! A Critical Inquiry into the History of Jesus of Nazareth: Being a Rational Analysis of the Gospels by Paul Henry Thiry Baron d' Holbach

He will come very near to us in his books, and by that subtile law of communion which, through the brightest and noblest utterances, makes all the better world akin.

From A Breeze from the Woods, 2nd Ed. by William Chauncey Bartlett

We rather think that far subtiler things than the doctrine of association had from of old been familiar to him.

From Life of Robert Burns by Thomas Carlyle

Is not the Heat of the warm Room convey'd through the Vacuum by the Vibrations of a much subtiler Medium than Air, which after the Air was drawn out remained in the Vacuum?

From Opticks or, a Treatise of the Reflections, Refractions, Inflections, and Colours of Light by Sir Isaac Newton

The Reflexion must have rather been caused by a subtiler Medium, which could recede through the Glasses at the creeping in of the Water.

From Opticks or, a Treatise of the Reflections, Refractions, Inflections, and Colours of Light by Sir Isaac Newton

No, his temperament needed a subtiler atmosphere than this, rarer essence than mere brutal freedom.

From The Atlantic Monthly, Volume 08, No. 50, December, 1861 by Various

Gradually he wove a drama round it; line by line it took shape for a book that was to be subtiler, finer and more sincere than anything that he had ever written.

From The Education of Eric Lane by Stephen McKenna

A book might be written on the Stratagems of Literature, as Frontinus has composed one on War, and among its subtilest heroes we might place this great poet.

From Calamities and Quarrels of Authors by Isaac Disraeli

He was the farthest reach of subtlety compatible with an individual self,--the subtilest of authors, and only just within the possibility of authorship.

From Beacon Lights of History, Volume 13 Great Writers; Dr Lord's Uncompleted Plan, Supplemented with Essays by Emerson, Macaulay, Hedge, and Mercer Adam by John Lord

As for me, Abraham, Isaac, and Jacob are now only the subtilest imaginable essences, which would not stain the morning sky.

From A Week on the Concord and Merrimack Rivers by Henry David Thoreau

This is a truth that takes all the sting out of Lord Bacon's observation that "against Atheists the very savages take part with the very subtilest philosophers."

From Flowers of Freethought (Second Series) by G. W. (George William) Foote

At some far-away period in childhood it got imbedded in my fancy, and in process of time had acquired that subtilest, indefinable fascination which belongs only to imaginative reminiscence.

From The Atlantic Monthly, Volume 15, No. 88, February, 1865 by Various