Difference between deductive and inductive method – Francis Bacon

Two were the methods used for a long time in science and philosophy whose purposes were the discovery of truth: the deductive method and the inductive method.

the deductive method

The deductive method, which was used by Aristotle, derives from the universal to the particular fact and, in this way, establishes principles and determines new axioms. It is linked to logical reasoning and presupposes the existence of universal and predetermined propositions, which serve as basic premises to reach the truth in specific, particular cases.

Thus, starting from such premises, the method arrives at a conclusion, and between such premises and conclusion there are a number of intermediate statements that are questioned until their acceptability can be assured. Gradually and through the affirmations that come to be accepted, the final conclusion is reached and a plausible argument is elaborated. His most developed technique is the syllogism, which was used by Aristotle.

the inductive method

The inductive method, used and defended by Bacon, starts from the senses and the particular to establish the axioms and then ascends in a continuous and gradual way to reach the most general axioms. Bacon makes points about the deductive and inductive methods:

There are and can only be two ways of investigating and discovering the truth. One, which consists in jumping from sensations and particular things to the most general axioms, and then discovering the intermediate axioms starting from these principles and their immovable truth. This is what now follows. The other, which collects the axioms from the data of the senses and particulars, ascending continuously and gradually until reaching, in last place, the principles of maximum generality. This is the true path, but not yet established (BACON, 2011, p. 84).

It is through this last path that particulars are discovered through observation and principles are also determined. This method advocates starting from observable situations to subsequently use reasoning and formulate statements and laws. In addition, there must be verification of specific situations before carrying out the judgment.

The purpose of the inductive method

The central objective of the inductive method is to establish the cause of natural phenomena and, for that, it requires the confirmation of theories through their results. As Bacon expounds on Novum Organum, the objective of science is to establish laws and, therefore, an extensive enumeration of the manifestations of any phenomenon must be made and, concomitantly, the registration of its variations must be carried out. From these records, results are obtained which will be tested by experiments, because: “Every true interpretation of nature is fulfilled with opportune and adequate instances and experiments, where the senses judge only the experiment and the experiment judges nature and the thing itself” ( BACON, 2011, p. 93).

As can be seen, Bacon proposes a return to things themselves and for that, the senses are conceived as the source of all valid knowledge when guided by the scientific method. Thus, the proposal of the inductive experimental method is essential to arrive at the most general principles of natural phenomena correctly, since it is starting from specific and observable facts, cataloging them, analyzing them and excluding contradictory ideas that one can arrive at the universal and also to new knowledge and the progress of science: “proceeding with the due rejections and exclusions, and then, then, in possession of the necessary negative cases, concludes about the positive cases” (BACON, 2011, p. 131).

Induction is a fundamental moment to acquire knowledge, since it serves to discover and demonstrate the principles, the minor and medium axioms and all the axioms and discover new particulars. The philosopher shows that science must follow the true scale, of continuous and flawless degrees, because from particular facts one goes to minor axioms, from these one goes to medium axioms and from these last ones one arrives at the most general ones. And when it turns to the analysis of nature, it is useful for the discoveries and demonstrations of the sciences and the arts.

Galvão (2007) points out that Bacon’s ideas, accompanied by his defense of experimentation and the inductive empirical method, portray the bases for modern science, given that the philosopher perceived the obstacles to scientific progress, progress that would have as results new discoveries useful to human life: “For the author of the novum organumscience is a tool for creating new knowledge that can be used to promote advances, well-being and progress for mankind” (GALVÃO, 2007, p. 37).

Bacon’s objective was to expand the power that man can exercise over nature and this would only be achieved through knowledge of nature, of the causes of phenomena through the inductive method. Given the equivalence between power (over nature) and knowledge (about nature), it can be seen that nature has come to occupy the locus foundation for the sciences, for intellectual life.

Even with all of Bacon’s concern regarding the observation of things in nature, cataloging and experimentation, one must keep in mind that the author proposes a middle ground between dogmatism and empiricism to arrive at true science:

The work of true philosophy is no different, which does not use only the forces of the mind, nor is it limited to the material provided by natural history or the mechanical arts, preserved innately in the memory. But it must be modified and elaborated by the intellect. Therefore, much should be expected from the close and solid alliance (not yet carried out) between these two faculties, the experimental and the rational (BACON, 2011, p. 127).

It is evident that the Baconian method is composed of the experimental and rational faculties, since the intellect is applied in an integral way to the particular facts and the experience becomes guided by safe laws, in a gradual and constant way. In summary, the path taken by the Baconian inductive method, unlike the Aristotelian method, has the following phases: eliminate the idols; to know the structure and law that regulates the process of the phenomenon; organize a comprehensive record of the history of the analyzed phenomenon through tables of presence, absence and degrees; enunciate the first vintage; testing the hypothesis by prerogative instances and, at the end, confirmation or not of the hypothesis (if it is not confirmed, one must return to the inductive process).

Such a proposal is opposed to the deductive method used by Aristotle, given that Bacon accuses him of allowing the intellect to: “jump and fly from particular facts to remote and, so to speak, more general axioms – which are the so-called principles of the arts. and of things — and then seek, from its immutable truth, to establish and prove the middle axioms. And this is what has been done until now thanks to the natural propensity of the intellect, accustomed and trained for a long time, by the use of syllogistic demonstrations” (BACON, 2011, p. 131).

As is known, Aristotle proposes the deductive method as an instrument of science and proposes experience as the basis of all knowledge. However, Bacon’s criticism of the Stagirite’s method rests, firstly, on the view of Aristotelian induction as a mere enumeration of particular cases, as it passes quickly over experience and over particular facts, not paying attention to both as much as necessary. The crucial difference, according to the modern philosopher, is that Aristotelian induction slips over the facts and his philosophy was corrupted by logic, by dialectics, while the method proposed in novum organum occurs by elimination and, therefore, has the capacity to apprehend the nature and essence of phenomena:

For Aristotle first established the conclusions, he did not properly consult experience for the establishment of his resolutions and axioms. And having so decided at his discretion, he subjected the experience like a slave to conform it to his opinions (BACON, 2011, p. 99).

For Bacon, the traditional inductive method has as characteristics the mere enumeration of phenomena, leading to judgment based on a smaller number of phenomena than necessary and, also, turning only to the phenomena that can be easily reached: “this method , which proceeds syllogistically from the most particular to the most universal, skipping the intermediate rings, leading to precarious conclusions and constantly exposed to the danger of contradictory theses” (REALE, 2009, p. 275).

Thus, Aristotle is accused of submitting natural philosophy to logic, leaving the sciences and philosophy only in the abstract, making both almost useless and slaves to their private opinions, which, in turn, led to the stagnation of new scientific discoveries.

For this reason, the modern philosopher proposes an alternative, a true scientific induction that uses many things, things that had not even been thought of before and that takes as a crucial point the analysis of the phenomena of nature starting from experiments, by exclusions and eliminations of cases in which the phenomenon is absent or not fully present. This is the only way to arrive at the most general causes and axioms linked to the phenomenon. Induction by elimination is therefore conceived as the interpretive key of nature.

In short, it can be noted that Bacon’s criticism of the Stagirite theory focuses on the deductive method and on the false Aristotelian inductive method:

The Aristotelian Induction (epagôge) aims more at communication than at the discovery of knowledge. It is essentially a verbal operation, a simple rigid model of argumentation, proceeding from words to words, not from words to things (OLIVEIRA, 2002, p.179.)

Specifically with regard to the deductive method, Bacon criticizes the lack of importance attributed to observations, since attention was turned to the functions of deductions: the beginning of procedures takes place with the first principles and using syllogisms, generalizations were carried out so precipitate. The English philosopher exposes the need for the observation and interpretation of nature (path to the interpretations of nature) according to safe and scientific methods (and no longer according to the anticipations of nature). Bacon also states that the Aristotelian deductive and inductive methods only order knowledge, without expanding it.

references

BACON, F. Novum Organum, or true indications concerning the interpretation of nature. Available in: SELL, S. Philosophical Discourse II: textbook. Palhoça: UnisulVirtual, 2011.

GALVÃO, RCS Francis Bacon: theory, method and contributions to education. Interdisciplinary International Journal InterThesis, Florianópolis, v. 4, No. 2, p. 32-41, Jul./Dec. 2007.

OLIVEIRA, BJ Francis Bacon and the foundation of science as technology.BH: UFMG, 2002.

REALE, G. History of Philosophy: From Humanism to Descartes🇧🇷 v. 3. São Paulo: Paulus, 2009.