Francis Bacon: "The Secretary of Nature" Bacon's real claim to fame is: not that he, as the lord chancellor, in 1621, was removed from office for accepting a litigant's bribe; nor, that he was the real writer of the Shakespearean plays (one of the controversies in English literature, the "Baconian controversy")3; but rather Francis Bacon is known as a philosopher, one of the first order. Bacon delineated the principles of the inductive method, which constituted a breakthrough in the approach to science, even though philosophers and scientists of the day, - and seemingly today, yet - repudiated both his theories and methodology, alike. Bacon argued that the only knowledge of importance to man was empirically rooted in the natural world; and that a clear system of scientific inquiry would assure man's mastery over the world. He was the originator of the expression, "Knowledge is power." He was quite taken up by the "materialist" theories and the resultant discoveries of both Copernicus and Galileo. Bacon, along with Galileo, are known in the literature as "the great anti-Aristotelians who created the 'modern scientific' view of Nature." Francis Bacon was born at London. He entered Trinity College, Cambridge, at the age of twelve. He studied law and became a barrister in 1582; two years later he took a seat in the House of Commons. His opposition, in 1584, to Queen Elizabeth's tax program retarded his political advancement. While in the earlier days he supported the Earl of Essex, Bacon, in 1601, was involved in his prosecution. With the accession of James I (1566-1625) and thereafter, a number of honours were bestowed on Bacon: he was knighted in 1603, made Solicitor General in 1604, Attorney General in 1613, and Lord Chancellor in 1618. He had powerful enemies, foremost among them was Sir Edward Coke. "Bacon and Coke were bitter political rivals, in Parliament and the law courts." They even contended for the hand of the same woman, a widow, Lady Elizabeth Hatton, - "beautiful, widowed, and rich."

Bacon, not having come from a rich family, and always pressed for money: accepted, and this is one of the great surprises of history, a litigant's bribe. This was in 1621; so, just four months after he was raised to the peerage, Bacon was evicted from office. ("I do plainly and ingenuously confess that I am guilty of corruption, and do renounce all defense.") Francis Bacon went into retirement and died in 1626; he was buried at Saint Michael's Church in St. Albans, just north of London, Hertfordshire
Francis Bacon's major contribution to philosophy was his application of induction, the approach used by modern science, rather than the a priori method of medieval scholasticism.

Up to and during Bacon's time there existed philosophies rooted not so much in reason but in pure faith; philosophies promoted by the church. [See Saint Anselm (1033-1109) and Thomas Aquinas' (1225-1274) and, more generally, the Scholastic School.] Bacon was "violently opposed to speculative philosophies and the syllogistic quibbling of the Schoolman ..., Bacon argued that the only knowledge of importance to man was empirically rooted in the natural world." "There are and can be only two ways of searching into and discovering truth. The one flies from the senses and particulars to the most general axioms: this way is now in fashion. The other derives axioms from the senses and particulars, rising by a gradual and unbroken ascent, so that it arrives at the most general axioms last of all. This is the true way, but as yet untried." Thus, Bacon delineated the principles of the inductive thinking method, which, while as a method goes back to the times of Aristotle, constituted a breakthrough in the approach to science. It was just these kind of materialist theories that brought about the great discoveries of Copernicus and Galileo. Bacon could see that the only knowledge of importance to man was empirically rooted in the natural world; and that a clear system of scientific inquiry would assure man's mastery over the world.5

Mill's Methods

Mill's Methods are five methods of induction described by philosopher John Stuart Mill in his 1843 book A System of Logic. They are intended to illuminate issues of causation.
Direct method of agreement

"If two or more instances of the phenomenon under investigation have only one circumstance in common, the circumstance in which alone all the instances agree, is the cause (or effect) of the given phenomenon."

For a property to be a necessary condition it must always be present if the effect is present. Since this is so, then we are interested in looking at cases where the effect is present and taking note of which properties, among those considered to be 'possible necessary conditions' are present and which are absent. Obviously, any properties which are absent when the effect is present cannot be necessary conditions for the effect.

Symbolically, the method of agreement can be represented as:
A B C D occur together with w x y z
A E F G occur together with w t u v
——————————————————
Therefore A is the cause, the effect, or part of the cause of w.
Method of difference

“If an instance in which the phenomenon under investigation occurs, and an instance in which it does not occur, have every circumstance in common save one, that one occurring only in the former; the circumstance in which alone the two instances differ, is the effect, or the cause, or an indispensable part of the cause, of the phenomenon.”

A B C D occur together with w x y z

B C D occur together with x y z

——————————————————

Therefore A is the cause, or the effect, or a part of the cause of w.
Joint method of agreement and difference

"If two or more instances in which the phenomenon occurs have only one circumstance in common, while two or more instances in which it does not occur have nothing in common save the absence of that circumstance: the circumstance in which alone the two sets of instances differ, is the effect, or cause, or a necessary part of the cause, of the phenomenon."

Also called simply the "joint method," this principle simply represents the application of the methods of agreement and difference.

Symbolically, the Joint method of agreement and difference can be represented as:
A B C occur together with x y z
A D E occur together with x v w also B C occur with y z
——————————————————
Therefore A is the cause, or the effect, or a part of the cause of x.
Method of Residue

"Deduct from any phenomenon such part as is known by previous inductions to be the effect of certain antecedents, and the residue of the phenomenon is the effect of the remaining antecedents."

If a range of factors are believed to cause a range of phenomena, and we have matched all the factors, except one, with all the phenomena, except one, then the remaining phenomenon can be attributed to the remaining factor.

Symbolically, the Method of Residue can be represented as:
A B C occur together with x y z
B is known to be the cause of y
C is known to be the cause of z
——————————————————
Therefore A is the cause or effect of x.
Method of concomitant variations

"Whatever phenomenon varies in any manner whenever another phenomenon varies in some particular manner, is either a cause or an effect of that phenomenon, or is connected with it through some fact of causation."

If across a range of circumstances leading to a phenomenon, some property of the phenomenon varies in tandem with some factor existing in the circumstances, then the phenomenon can be attributed to that factor. For instance, suppose that various samples of water, each containing both salt and lead, were found to be toxic. If the level of toxicity varied in tandem with the level of lead, one could attribute the toxicity to the presence of lead.
Symbolically, the method of concomitant variation can be represented as (with ± representing a shift):
Unlike the preceding four inductive methods, the method of concomitant variation doesn't involve the elimination of any circumstance. Changing the magnitude of one factor results in the change in the magnitude of another factor.