“The Definition in the Elements, according to Clavius, is this: Magnitudes are said to be in the same Reason [ratio], a first to a second, and a third to a fourth, when the Equimultiples of the first and third according to any Multiplication whatsoever are both together either short of, equal to, or exceed the Equimultiples of the second and fourth, if those be taken, which answer one another…. Such is Euclid’s Definition of Proportions; that scare-Crow at which the over modest or slothful Dispositions of Men are generally affrighted: they are modest, who distrust their own Ability, as soon as a Difficulty appears, but they are slothful that will not give some Attention for the learning of Sciences; as if while we are involved in Obscurity we could clear ourselves without Labour. Both of 300 which Sorts of Persons are to be admonished, that the former be not discouraged, nor the latter refuse a little Care and Diligence when a Thing requires some Study.”
Source: Mathematical Lectures (1734), p. 388
Help us to complete the source, original and additional information
Isaac Barrow 20
English Christian theologian, and mathematician 1630–1677Related quotes

As quoted by Lama Surya Das, Huffington Post April 28, 2010 http://www.huffingtonpost.com/lama-surya-das/spiritual-life-wisdom-an_b_552927.html.

Disme: the Art of Tenths, Or, Decimall Arithmetike (1608)
1922 Source: Geraldine Taylor. Behind the Ranges: The Life-changing Story of J.O. Fraser. Singapore: OMF International (IHQ) Ltd., 1998, 269.

Lives of the Ten Orators
Bartlett's Familiar Quotations, 10th ed. (1919)

Interview on Charlie Rose https://archive.org/details/WHUT_20100614_130000_Charlie_Rose (2000)

The Architecture of Theories (1891)
Context: The origin of things, considered not as leading to anything, but in itself, contains the idea of First, the end of things that of Second, the process mediating between them that of Third. A philosophy which emphasises the idea of the One, is generally a dualistic philosophy in which the conception of Second receives exaggerated attention: for this One (though of course involving the idea of First) is always the other of a manifold which is not one. The idea of the Many, because variety is arbitrariness and arbitrariness is repudiation of any Secondness, has for its principal component the conception of First. In psychology Feeling is First, Sense of reaction Second, General conception Third, or mediation. In biology, the idea of arbitrary sporting is First, heredity is Second, the process whereby the accidental characters become fixed is Third. Chance is First, Law is Second, the tendency to take habits is Third. Mind is First, Matter is Second, Evolution is Third.