The Role of Reasoning in Science: Inductive and Deductive Approaches

Introduction

This essay will focus on the principles of the scientific method, considering Francis Bacon’s method of induction contrasted with Karl Poppers’ Hypothetico-Deductive approach as a means of defining what is scientifically accurate. Both approaches are used in modern-day science, where experiment and observation are fundamental when accumulating scientific research. Having a standardized approach to testing is essential for reliability purposes. Being a scientist means questioning without sufficient evidence and interpret observations to a degree that either supports or contradicts a hypothesis. Both approaches aim to solve the scientist’s problem, although there is no one true method that fits all branches (Rothchild, 2006).

A scientific method in a general sense is a procedure by which a systematic approach is made to how we process science. Through observation and experimentation, the type of reasoning that is used, whether it is inductive or deductive, and the formulation and rigorous testing of hypotheses. These all aim to demarcate what is considered science from non-science, although the scientific method that is followed vary in how they are carried out (Anderson & Hepburn, 2015).

Induction

Francis Bacon, A philosopher in the 17th century introduced the idea of Induction. A scientific method describes theory building through a process of observation, followed by a generalization (Susser, 1996). This means transitioning from inspection of particular instances to collecting facts and data to formulate common features. Ultimately, a hypothesis is built upon these patterns which scientists set out to either confirm or prove the theory. (LiveScience, 2017) An example of inductive reasoning would go as follows; Eating a piece of bread that is nourishing would suggest the next piece will also be the same without observing the result. This justification is an inductive inference in that a generalization has been predicted without having observed the outcome (Henderson, 2018).

Despite induction being first introduced during the Aristotelian era, it is seen as the weaker of the two methods of scientific inference. In comparison, the deduction was concrete in what it classed as truth and held ancient rules that were well known. Induction follows a ‘bottom-up’ approach, depicting movement from the particular to the general, following the Aristotelian notion. However, Bacon also believed that effective knowledge progressed through inductive means which lead to conclusions about the world. He also emphasized how important experimentation and observation were, which both scientific methods can agree are essential when deciding what is scientifically accurate (Mahootian & Eastman, 2010).

Deduction

An influential philosopher of science in the 20th century, Karl Popper, proposed the hypothetico-deductive approach, which theorized that for a concept to be considered science, it was necessary that it could be proven untrue. (Gauch, 2003) The method is therefore structured on the basis that a hypothesis can be made falsifiable, such that there must be a negative answer to the hypothesis (Bradford, 2017). He outlines the steps in the scientific method as firstly observing facts and gathering information, followed by proposing a theory based on those facts. This corresponds with the inductive method, though Popper says to deduce the consequences of the prediction. Therefore to ask, if the theory is correct, what will follow from it? He insists that a conclusion is only made to the point at which it can be rejected. If the prediction withstands after experimentation, it is accepted to a higher degree but crucially never proved. The understanding is thus provisional (Mahootian & Eastman, 2010).

He highlights that validation is unattainable since it is impossible to carry out every possible experiment and analyze those results. Using the example from an observation of a sample of white swans, induction would conclude that all swans must consequently be white based on experience. However, Popper would argue that this is illogical as one observation of a black swan would falsify this premise, demonstrating the fundamental problem of induction. Popper's philosophy is therefore based on falsification and is how he interprets science should work (Susser, 1996).

Popper agreed with an 18th-century philosopher, David Hume, who suggested that the inductive approach was not rational in logic due to many factors. Hume pointed out that it is unreasonable to assume the future will follow the same rules that apply today; the foundations of science are insecure considering discoveries are constantly being developed. Popper’s ideal method is therefore to present new theories, refute the poorly evidenced with conflicting data, and acknowledge those that remain in a careful manner (Gauch, 2003). In essence, deductive reasoning moves from the general to the particular. Essentially hypothesizing a theory followed by observations to provide evidence to back up the original idea. In contrast, inductive reasoning is the opposite, moving from specific observations to a broad generalization.

To conclude, the inductive method has been far more criticized by the likes of Hume than the deductive method, Yet It is speculated that the deductive approach halts the progress of science as it’s a far older method. Kant, an 18th-century philosopher, declared that leaves little room for human imagination in a sense that philosophers such as Kuhn, in the 20th century, state that the human mind isn’t capable of understanding reality therefore scientific certainty about the real world was impossible. Ultimately meaning that induction was invalid. This skepticism portrays how those in favor of the deductive approach are less open to the idea of predictive thinking. This leads on to the question of how theories are formed if not by incorporating findings through inductive means to which Popper did not have the answer to (Locke, 2007).

Complementary approach

In some cases, there is a blend of both types of approaches. A researcher may investigate one part of their study with a deductive approach and the other using induction. By researching other scientists' work, a general theory can be made, and experimentation can be carried out, which would follow a deductive approach. This would provide new evidence that could be explained through inductive means hence a complementary approach (Decarlo, 2018). 

Conclusion 

In conclusion, both Francis Bacon’s method of induction and Karl Popper’s hypothetico-deductive approach have their advantages and disadvantages when it comes to defining what is scientifically accurate. Bacon’s inductive approach involves making generalizations based on observations and patterns, while Popper’s deductive approach requires that a hypothesis be falsifiable. Both approaches agree that experimentation and observation are fundamental in accumulating scientific research. While the deductive approach has been criticized for halting the progress of science, the inductive approach has also been criticized for its weakness compared to the deductive approach. Ultimately, it is necessary to take a complementary approach that takes into account the strengths of both methods in order to obtain a more complete understanding of scientific phenomena.