A logic is the system or set of principles underlying the arrangement and behavior of elements in a system. All ordered systems have a set of relationships between their parts that defines how the whole system and its parts behave. This set of interrelationships that defines the parts is the logic of the system. For example, there is a logic to the behavior of a horse, because it is defined and governed by a set of interrelations between its elements and its connections with its broader environment. A horse will exhibit certain behavior as a product of this set of interrelationships. If we give the horse some hay and some meat it will eat the hay not the meat, this behavior to the horse is governed by a logical set of relations between it parts and its environment and this we would say is the logic governing the horse’s behavior; in this case the fact that its digestive system is designed to process hay, not meat.
Logic refers to the interrelationships between things, the fact that there is some order to those interconnections and through them, the behavior and features of the parts are defined by the whole organization and the logic of its interrelationships. The logic to a shop, and how to run a shop, is governed by the many things that it is interconnected with, customers, suppliers, local and global economy etc. When the shop owner decreases the price of some product, she does this according to some set of logical relationships with the other elements; because she believes it will attract more customers into the shop, or because they have just received a discount delivery, or they are overstocked etc. The shop owner is acting logically because she is acting in accordance with the logic of being a shop own; the set of interrelationships with other things that this entails. Likewise, all systems have a logic that governs their behavior and it is through that set of interconnections that the parts are defined. For example, we can not understand what a mother is without understanding what a child is. It is the logic between them that defines each and creates a dynamic that drives their behavior. To properly understand what parenting is one has to in fact understand a whole myriad of things such as at least the idea of a child, the idea of birth, the idea of youth, of responsibility, nurturing etc. One has to understand all of these things to understand the idea of being a mother because the mother’s state and behavior are defined by her interrelationship with all of these other factors and the logical set of interrelationships between them.3
This idea that there is a logic behind things is a central premise of critical thinking and science. Science presumes that the things and events in the universe occur in some constant and intelligible patterns that are comprehensible through careful, systematic study. Scientists believe that through the use of reason, and with the aid of instruments, people can discover patterns in all of nature.4 The fundamental assumption of all of science is that the world around us is logical in some way. That means that there is some pattern to the relationship between things and events that can be understood intelligibly and this forms the logic of a particular domain. We can say then, that it is this logic that researchers within a particular domain are trying to use reason to discover. In this sense, all domains of study and science represent a particular logic.5 A subject then is a set of ideas that are interrelated in a logical way to try and capture the logic behind some system in the world. Things have a meaning and definition as part of a broader system of logic that defines them. To understand what something means one has to understand the logic governing the broader system it is a part of. In reasoning, one tries to figure out this logic of things, because in a system that exhibits any degree of complexity its dynamics or logic will not be manifest, one will simply see events, possibly some associations will be manifest but not all, and it requires systematic thinking in the form of reasoning to derive the underlying logic. One can say then that learning a body of content, say, an academic discipline, is equivalent to learning to think within that discipline. Hence to learn biology, one has to learn to think biologically. To learn sociology, one has to learn to think sociologically. Biologists are trying to construct the logic of living things, physicists are trying to figure out the logic of physical systems, sociologists are trying to understand the logic behind social systems etc.6
It is in this sense of logic that the idea of objective knowledge can have foundations. To have objective knowledge is to understand how something really works, which is equivalent to understanding the logic of the system under consideration. Knowledge, that is of value is knowledge that is objective, which means that it is relevant within many frames of reference, it stays working under many different circumstances and this can only be achieved by understanding the deep logic to the system. A piece of knowledge that is only applicable under certain circumstances, only applies to certain people, or cultures, is of less value than knowledge that is relevant to all situations. This more objective knowledge is a product of understanding the broader logic behind the system. With critical thinking, one is not doing philosophy, in searching for deep metaphysical Truth with a capital T, but like science critical thinking is much more practical, it is in search of knowledge that works and stays relevant independent of place, time, society or culture. Critical thinking and science are standards and methods for a process of inquiry that will help us develop objective knowledge, knowledge that works and has value independent of anyone’s evaluation. It is by understanding the logic of photons that we can create lasers and any society, anywhere on the planet now can create lasers, by understanding the logic to the human body we can cure diseases, with the logic of energy conversion that is captured in the knowledge of thermodynamics, we can send rockets to the moon. But in order to understand this objective logic it is required that our subjective conceptions are shaped to conform with the external logic of the systems we are considering, not the other way round. This is – or has in the case of science been – achieved through the application of objective standards and methods.