Maharashtra Board Class 12 Logic Chapter 6 Grounds of Induction PDF Download

Grounds of Induction

There is a difference between perception and observation.

Observation needs training.

Science involves experiments that can be repeated by others.

Introduction

The aim of the scientific investigation is to understand the nature of the universe. When a scientist observes nature, certain facts are clear to him; whereas certain facts are not. They explain these problems by discovering different laws and establishing theories. Laws in science are established by induction, which proceed from observed to unobserved, known to unknown, where the evidence is about some cases but the conclusion is about all cases, such a leap from 'some to all' is called as an Inductive Leap which makes the conclusion of an argument probable. Hence there is a need to justify Inductive Leap.

Inductive leap is justified on two grounds, namely, formal grounds of induction and material ground of induction

Formal Grounds Of Induction

Principle of uniformity of nature and Principle of Causation are called 'Formal grounds of Induction'.

The Principle Of Uniformity Of Nature

It states that there is an order in nature. Whatever happens once will always happen again under similar circumstances. So on the basis of this principle, it is justified in arguing that what is true of some case of a kind is true of all the cases of that kind.

The Principle Of Causation

It states that some events in nature are causally connected and causal relation is invariable i.e. the same cause always leads to the same effect.

Thus on the basis of these two principles, the Inductive Leap is justified

Material Grounds Of Induction

The aim of induction in science is to arrive at laws or theories on the basis of particular facts. Science aims at establishing the material or empirical truth of laws. For this, formal ground is not enough. Material truth of empirical laws is established by the methods of observation and experiment. Therefore these methods are called material grounds of induction. They provide the initial data to scientist for enquiry.

Teacher's Note

When a doctor checks your body temperature, the doctor is doing observation. The doctor has a purpose - to find out if you have fever.

Exam Trick

Remember: Observation has a purpose. Perception does not have a purpose. Just like you look at your phone screen on purpose, observation also has purpose.

Points to Remember

Observation means looking at something with a clear purpose.
Perception is just noticing things without any purpose.
Every observation is perception but every perception is not observation.

Observation

The word observation is derived from two Greek words, 'Ob' means 'before' and 'server' means 'To keep'. So observation literally means 'keeping something before the mind'.

One gets knowledge of the world around us through the five sense organs. Whenever one looks around one notices many objects and their qualities. This is perception. Perception is to become aware of objects and events that happen to come to our notice. There is no definite purpose in perception and it is not deliberately chosen. So perception differs from observation due to these characteristics.

For example: when one passes by a corridor besides a chemistry laboratory, one becomes aware of some smells; one listens and hears sounds of various kinds. But this is not observation. It is mere perception.

Observation is defined as selective perception of facts with a certain purpose. So every observations is perception but every perception is not observation unlike perception observation is purposive and selective.

Difference Between Observation And Perception

Teacher's Note

A teacher looking for good students is observing. A teacher just seeing all children sitting is perception. Observation has a purpose, perception does not.

Exam Trick

Remember: Observation = Purpose + Selection. Perception = No purpose + No selection. Think of it like shopping with a list versus just walking around a mall.

Points to Remember

Observation is selective perception with a clear purpose.
Perception happens to us without any planning.
Scientists use observation, not just perception.
Every observation is perception but not every perception is observation.

Characteristics Of Observation

Observation is done by common man as well as scientist but the scientific observation is systematic. It is the foundation of scientific investigation.

Following are the characteristics of observation.

Observation Is Purposive

When the scientist proceeds to observe nature he does so with a definite purpose. The main purpose is to collect data or facts, on the basis of which one can either prove or disprove a theory.

Thus it is purposive. e.g. Discovery of Neptune.

Observation Is Selection Of Significant Facts

Observation is selective. Selection of facts is determined by the observer's purpose. From the countless facts in the world, scientists select to observe only those facts which are relevant to the problem under study. He observes only those significant facts that would help him to either establish or reject the suggested hypothesis.

Observation Is Selection Of A Significant Aspect Of Fact

Facts are vast and complex. There are many aspects to facts. It is neither necessary nor possible to observe all the aspects of facts. The observer therefore focuses attention only on the significant aspects of a fact, which are relevant to the hypothesis under consideration.

For example: When a doctor visits his patient he observes his blood pressure, temperature, heartbeats etc., as they are significant aspects for patient's health. Whereas a friend or a relative of the patient equally concerned about him may not observe these aspects. So though the fact (the patient) observed is the same, the aspect of facts considered significant can differ with each observer.

The Observer Has To Neglect The Illusory Aspects Of A Fact

Our sense organs are means of observing facts. Sometimes our senses can deceive us and we may experience illusions.

For example: A stick looks bent when a part of it is immersed in water. This experience is an illusory aspect of fact and one should overlook it as a matter of optical illusion which is due to the refraction of sun rays. This needs to be neglected during observation.

Teacher's Note

When you see a stick in water looking bent, your eyes are fooling you. A scientist knows this is just an illusion and does not record false information.

Exam Trick

Remember: Observation has 4 main features - purposive, selective, significant aspect, and ignore illusions. Write these four points in your exam and you will get full marks.

Points to Remember

Observation is done with a clear purpose or goal.
Only important and relevant facts are observed.
Scientists focus on significant aspects only.
False illusions must be ignored during observation.
Observation uses our five senses with clear thinking.

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