What is Philosophy
What is Philosophy
of Science
What is Verification
and Falsification
about Science
Science according to
Scientific method
Paradigm and
paradigm shift
Karl Popper -
Logic and status
Consequences of Popper's theses
Alternative Science
Chalmers: What is this
thing called Science?
Epistemology -
induction deduction

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. Scientific methodology 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 describes 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

From: John Losee - A Historical Introduction to the Philosophy of Science, 4Ed (2001):

Aristotle described the stages when hypotheses are created:


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

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

These stages are called The Inductive - Deductive Method and are still relevant during investigations of new phenomena.

The method implies that an unknown phenomenon is investigated using observations and that, from these, a hypothesis about the properties of the phenomenon is created using induction. Consequences of the hypothesis is inferred using deductive arguments, and the consequences are tested using additional observations, giving three possible outcomes:

• The hypothesis is further confirmed
• The hypothesis is not at all in accordance with our experienced reality
• The hypothesis needs to be modified.

The opinion that this methodology represents a fruitful methodology in investigations of some new phenomenon was shared 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 inductive-deductive method is sometimes erroneously called the hypothetico-deductive method, which actually is a method for hypothesis testing. A writer that claims that the hypothetico-deductive method is a scientific method has not understood that the hypothesis was created based on that something was observed, or from earlier created hypotheses that originally were based on observations.

This mistake is not uncommon among armchair philosophers (rationalists).

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

Resolution and Composition or Analysis and Synthesis (Composition)

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.

Isaac Newton (1642–1727) called the inductive stage for Synthesis and the deductive stage for Analysis. 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" (demonstratively valid argument).


In modern literature, confusion exists about the terms regarding the inductive and deductive stage, respectively. Both AC Crombie: Robert Grosseteste and the Origins of Experimental Science (1971) and Losee (ref. see above) 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 seen in H Gauch: Scientific method in practice (2003) p.224. This use of terms also explains Immanuel Kant's use of "synthetic", implying composition, or addition of e.g. observations into new information, and of "analytic", implying that something that is already known is divided into separate statements.

In order to avoid future mistakes in this matter during discussions of the scientific method, it would be more suitable to reverse the expressions and call the method for Composition and Resolution or Synthesis and Analysis.

Summary for the confused:

The inductive-deductive method is a scientific method according to Aristotle. The hypothetico-deductive method is a method to test hypotheses (directly or indirectly created from observations).

Inductive stage: Composition, synthesis (synthetic argument).

Deductive stage: Resolution, analysis (analytic argument).



Descartes (1596-1650) about scientific method

Descartes was a rationalist, i.e. he 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 our world were totally erroneous, even for that time.

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 (according to F. Hals)

Within philosophy it i known that Rene Descartes (1596-1650) discussed a scientific method in the book "Discourse on the Method...". The method 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 (1642-1727) about inductive - deductive method

Newton describes 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 he, like many others, has misunderstood the names of the concepts 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 - Opticks 4Ed (1730) p.380

Hume (1711-1776) about inductive - deduktive 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 - Enquiry... (1777) 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.

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 are viewed as reliable.


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


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