Only within the 20th Century has biological thought been focused on ecology, or the relation of the living creature to its environment. Awareness of ecological relationships is or should be the basis of modern conservation programs, for it is useless to attempt to preserve a living species unless the kind of land or water it requires is also preserved. So delicately interwoven are the relationships that when we disturb one thread of the community fabric we alter it all perhaps almost imperceptibly, perhaps so drastically that destruction follows.
There is (so to speak) "a mighty stream of tendency" to good in the human mind, upon which all objects float and are imperceptibly borne along; and though in the voyage of life we meet with strong rebuffs, with rocks and quicksands, yet there is a "a tide in the affairs of men," a heaving and a restless aspiration of the soul, by means of which, "with sails and tackle torn," the wreck and scattered fragments of our entire being drift into the port and haven of our desires!william hazlitt
Books have always a secret influence on the understanding; we cannot at pleasure obliterate ideas: he that reads books of science, though without any desire fixed of improvement, will grow more knowing; he that entertains himself with moral or religious treatises, will imperceptibly advance in goodness; the ideas which are often offered to the mind, will at last find a lucky moment when it is disposed to receive them.samuel johnson
Economic problems have no sharp edges. They shade off imperceptibly into politics, sociology, and ethics. Indeed, it is hardly an exaggeration to say that the ultimate answer to every economic problem lies in some other field.kenneth boulding
Gargoyles were the complement to saints; Leonardo's caricatures were complementary to his untiring search for ideal beauty. And gargoyles were the expression of all the passions, the animal forces, the Caliban gruntings and groanings which are left in human nature when the divine has been poured away. Leonardo was less concerned than his Gothic predecessors with the ethereal parts of our nature, and so his caricatures, in their expression of passionate energy, merge imperceptibly into the heroic.kenneth clark
The arbitrary rule of a just and enlightened prince is always bad. His virtues are the most dangerous and the surest form of seduction: they lull a people imperceptibly into the habit of loving, respecting, and serving his successor, whoever that successor may be, no matter how wicked or stupid.Denis Diderot
There is no passion that steals into the heart more imperceptibly and covers itself under more disguises than pride.joseph addison