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Scientific method


"Scientific method" is a term that is used during discussions about scientific activity. The term is not strictly defined as mentioned at the page Opinions about science.

Today "Scientific method" implies recommendations about how results from investigations should be reported. The method is an answer to that we cannot claim the existence of absolutely certain knowledge.

In spite of that Science is not the same as knowledge, many authors within the field of philosophy of Science confuse these concepts


The basis of scientific methodology is a careful description of what was observed and how observations were obtained. This method to increase the credibility of an account has been known since ancient times. One example is the seven questions within rhetoric during argumentation towards "logos", the intellect:

Who, What, Why, When, Where, How, By whose help


Background - How to perform investigations


What we today call Science was more widely spread during the 17th century and onwards. Before scientific methodology was more firmly established, many scientists and philosophers expressed how Science should be performed and why Science should be performed in those manners.


The basis was, and still is, that observations or logical connections should be described in such a detailed manner that they can be reproduced. This increases the possibility to estimate the probability of that the observations, calculations or hypotheses that was generated are in accordance with our experienced reality.


Inductive - deductive method


Already Aristotle discussed the Inductive - deductive method that still is relevant during investigations of new phenomena.

• The first stage implies that observations are generalized to principles.

• The second stage implies that these principles are used during observations.

Losee (2001) - A Historical Introduction to the Philosophy of Science, 4Ed, p.5-8.

One or several observations or earlier hypotheses make us believe in something, implying that we create an hypothesis. in case we want to investigate whether it confirms with our experienced reality, we repeat or check the observations.


When the hypothesis has been verified through credible investigations, it may be used as a starting point during investigations of our experienced reality.

This method represents a fruitful approach in investigating new phenomena, which was discussed e.g. by Roger Bacon (~1214-1292), John Duns Scotus (~1265-1308), Francis Bacon (1561-1626), Galileo Galilei (1564-1642) and Isaac Newton (1642~1726).


"Hypothetico-deductive method"


The method above is sometimes erroneously called the "hypothetico-deductive" method, and then it was not understood that the hypothesis originally was created based on observations.

"Hypothetico-deductive method" is a method for investigating consequences of hypotheses that already have been created.

Aristotle supposes that once we have gained scientific understanding, we are in a position to package our results in tidy demonstrations.


He does not think, as he is sometimes parodied as maintaining, that science proceeds by manufacturing demonstrations out of thin air, or without observation or investigation.

Rather, the demonstrations he puts forwards as canonical science are the polished results of investigation, made perspicuous by conforming to simple patterns of logical inference.

Shields (2007) - Aristotle, p.116-117.


Synthesis and analysis

In philosophic literature induction and deduction are renamed in several terms. A common example is Synthesis and Analysis, two terms involved in significant confusion, and another is the clearer Composition and Resolution.


Robert Grosseteste (~1168-1253) referred to the inductive stage according to Aristotle as a Composition of phenomena, in which elements are combined, and to the deductive stage as a Resolution of the phenomenon into its constituent elements.

Newton had, like many else, a unclear opinion about the meaning of the terms Synthesis and Analysis, as seen in the citation below.

Authors that expressed how hypotheses are created were well aware of that the inductive stage only resulted in probable "knowledge" and not in "absolutely certain knowledge" (i.e. not in demonstratively valid arguments).

In modern literature, confusion are found about the terms regarding the inductive and deductive stages, respectively:


Both Crombie (1971) - Robert Grosseteste and the Origins of Experimental Science and Losee - A Historical Introduction to the Philosophy of Science 4Ed confused the two. A reason for the confusion may be that scientific method and hypothesis testing were mixed up.

The same use of terms as used by is e.g. seen in H Gauch (2003) - Scientific method in practice, p.224.

This same use of terms also explains Immanuel Kant's use of "synthetic" for statements that combine, or add e.g. observations into new information, and of "analytic", for statements that divide something already composed (and hence "known") into separate statements.


Descartes about scientific method


René Descartes (1596-1650) was a rationalist that believed in pure deduction, and overlooked the importance of the inductive stage, Composition or Synthesis. His hypotheses were therefore based on substandard observations and resulted in that some of his discussions about the world were totally erroneous, even for that time being.

Examples include his discussion about blood circulation, based on observations of heating in a haystack, and that our planet system was built like a vortex, based on corks floating in water. He also gave his definition of the term "truth", based on that a benevolent god would never deceive him.

Descartes (F. Hals)

Within philosophy it is said that Descartes discussed a scientific method in the book "Discourse on the Method...". The method actually is about hypothesis testing and shows similarities with the method of Resolution or Analysis according to above.

The method consists of four steps:

• We shall never accept anything for true which we do not clearly know to be such. True is when something is presented so clearly and distinctly as to exclude all ground of doubt.

• To solve problems in the best way, they should be divided into as many parts as possible.

• You start to solve the easiest of the partial problems first.

• The result should be reviewed so general that it is assured that nothing was omitted.

Descartes also discussed additional factors which should be applicable when we want to investigate the world.


Newton about inductive - deductive method


Isaac Newton (1642-1727) described a synthetic - analytic workflow, implying that observations using induction are synthesized, or added, to general rules, and that later these general rules through analysis or dividing, are used to explain additional observable phenomena.

Unfortunately Newton, like many others, misunderstood the names of the concepts he used:

As in Mathematicks, so in Natural Philosophy, the Investigation of difficult things by the Method of Analysis, ought ever to precede the Method of Composition.

This Analysis consists in making Experiments and Observations, and in drawing general Conclusions from them by Induction, and admitting of no Objections against the Conclusions, but such as are taken from Experiments, or other certain Truths. For Hypotheses are not to be regarded in experimental Philosophy.


And although the arguing from Experiments and Observations by Induction be no Demonstration of general Conclusions; yet it is the best way of arguing which the Nature of Things admits of, and may be looked upon as so much the stronger, by how much the Induction is more general.

And if no Exception occur from Phænomena, the Conclusion may be pronounced generally. But if at any time afterwards any Exception shall occur from Experiments, it may then begin to be pronounced with such Exceptions as occur.

By this way of Analysis we may proceed from Compounds to Ingredients, and from Motions to the Forces producing them; and in general, from Effects to their Causes, and from particular Causes to more general ones, till the Argument end in the most general.

This is the Method of Analysis: And the Synthesis consists in assuming the Causes discovered, and established as Principles, and by them explaining the Phænomena proceeding from them, and proving the Explanations.

Isaac Newton (1730) - Opticks 4Ed, p.380


Hume (1711-1776) about inductive - deductive method


Hence likewise the benefit of that experience, acquired by long life and a variety of business and company, in order to instruct us in the principles of human nature, and regulate our future conduct, as well as speculation.

By means of this guide, we mount up to the knowledge of men’s inclinations and motives, from their actions, expressions, and even gestures; and again descend to the interpretation of their actions from our knowledge of their motives and inclinations.

David Hume (1777) - Enquiry... p.84-85


Scientific method - summary


An overview of the page Science according to is given below:

"Scientific method" involves routines to report observation results in a manner to permit estimates of their reliability. The method is primarily defined through requirements for acceptance in scientific journals.


The observations and results should be placed in a context: Previous significant results within the area should be reviewed.

Documentation and reproducibility

Conclusions should be based on observation results, or on earlier published results given with reference to the source.

Observations and results should be described in a manner so that they can be reproduced, i.e. be remade in the same manner by an external researcher.

Theoretical works

Theoretical works may also be based on other's published theories. In the beginning of chains of such works, it should always be present a hypothesis that was verified using observations. References are also here very important; the relations forming the work should be possible to control.

Peer review

To decrease the risk for errors in a report, it should be approved by independent scientists before it is published.

Additional verification

Pioneering discoveries, i.e. results that change present beliefs, should be verified by independent scientists before they may be comprehended as reliable.


In case the reported results may give rise to various conclusions, these should be discussed.