“Science is a magnificent force, but it is not a teacher of morals. It can perfect machinery, but it adds no moral restraints to protect society from the misuse of the machine. It can also build gigantic intellectual ships, but it constructs no moral rudders for the control of storm tossed human vessel. It not only fails to supply the spiritual element needed but some of its unproven hypotheses rob the ship of its compass and thus endangers its cargo.”

Sādhanā : The Realisation of Life http://www.spiritualbee.com/spiritual-book-by-tagore/ (1916)
Context: The human soul is on its journey from the law to love, from discipline to liberation, from the moral plane to the spiritual. Buddha preached the discipline of self-restraint and moral life; it is a complete acceptance of law. But this bondage of law cannot be an end by itself; by mastering it thoroughly we acquire the means of getting beyond it. It is going back to Brahma, to the infinite love, which is manifesting itself through the finite forms of law.

Source: The Birth of Fascist Ideology: From Cultural Rebellion to Political Revolution, 1994, p.7

Section 2 : Religion
Founding Address (1876), Life and Destiny (1913)

1980s
Source: Interview in Reason Magazine (1983).

Widely attributed to Gandhi, sometimes citing Ramachandra Krishna Prabhu, The Moral Basis of Vegetarianism (1959). (Cf. Ralph Keyes, The Quote Verifier (2006), p. 74.) However, it is not found in that essay http://www.mkgandhi.org/ebks/moralbasis_vegetarianism.pdf nor in any of Gandhi's Complete works. http://animalsmattertogod.com/2013/09/13/mahatma-gandhi-hoax-quote-greatness-of-a-nation-and-its-moral-progress-can-be-judged-by-the-way-that-its-animals-are-treated/
The original quote seems to be by David Strauss, The Old Faith and the New (Der alte und der neue Glaube, 1872, trans. by M. Blind, New York: Henry Holt & Co., 1873), vol. II, ch. 71, p. 59 https://archive.org/stream/oldfaithnewconfe01stra#page/59/mode/2up: The manner in which a nation in the aggregate treats animals, is one chief measure of its real civilization.
Similar quotes, not attributed to Gandhi, are found throughout the twentieth century: e.g. The great actress, Mrs Fiske, once said to me, "The civilization of any country can be told by the way it treats its animals" (Zoe Berkeley, "Zoe Berkeley's Corner", Salinas Index-Journal, 1933-07-01, p. 8).
Attributed to Gandhi since at least 1980: The seal hunt truly is Canada's shame and we would do well to think of the words of Gandhi when he said, "The greatness of a nation and its moral progress can be judged by the way its animals are treated" (Doris Potter, Letter to the editor, The Gazette (Montreal), 1980-03-18, p. 8).
Disputed

Variant: The ultimate test of a moral society is the kind of world that it leaves to its children.

Source: 1960s, Economics As A Moral Science, 1969, p. 12