Introduction: On Logic, Premises, and Conclusions
For a more in-depth review of these concepts, check out this khan academy link. From a cursory glance it appears well-written and accurate.
There are two commonly taught methods for reasoning, those being inductive and deductive approaches. These descriptions I am using are more formal in their language, for clarity’s sake. These methods can be used informally and conversationally, and I suspect every reader of this piece can come up with examples of using these methods themselves. That said, informal use of these methods, especially when not done rigorously, can lead to erroneous and problematic conclusions and decisions.
Induction- Usually described as using observations and evidence to move onto more general conclusions.
For example: The sun appears to have risen in the morning yesterday, the day before, the day before, etc. Thus, perhaps the sun rises every morning
Induction is limited by the fact that all of one’s observations can be generally correct at the same time as their conclusion is false.
For example: I see 10 swans, and all are white. Thus, perhaps all swans are white. Clearly, not all swans are white, as the existence of black swans is well documented. That said, if one were to do a wildlife survey, they would still get solid results if they were to assume all swans are white.
Deduction- Usually described as using explicit or implicit premises in order to arrive upon conclusions. A premise is some idea that is taken to be correct. In essence, deductive reasoning is built around the idea that if all premises are true, then the conclusion must also be true.
For example: Premise 1- All humans are mortal
Premise 2- Captain Kirk is a human
Conclusion- Captain Kirk is mortal
Deduction is limited by difficulties in confirming whether premises are correct or not. If one were mistaken about Captain Kirk being human, then there is the potentiality that he isn’t mortal (but he could be!).
One can also use the premise/conclusion format to create invalid arguments, so watch out for those. Sometimes their flaws are far less obvious than this one.
For example: Premise 1-Captain Kirk is human
Premise 2- Captain Picard is human
(Improper) Conclusion- Captain Kirk is Captain Picard
Upstream/Downstream: Ordering of thoughts
Streams flow from higher elevation to lower elevation. I find this to be a helpful metaphor for understanding the beliefs of oneself and others. This metaphor has been beneficial for organizing my own thoughts. Additionally, it has been useful in understanding disagreements/miscommunications that I have with others.
I have given brief summaries of inductive and deductive reasoning in order to articulate the background for how I use this metaphor.
For my own thought organization: I use the stream metaphor to help better outline my own evidence, premises, and conclusions. Upstream is the direction of initial premises or pieces of evidence, and downstream is the progression toward my conclusions on the subject. Here my conclusions flow from my earlier thoughts.
This sort of exercise assists me in writing cohesive and thoughtful texts. It especially assists me in being thorough in explaining my entire reasoning process, instead of jumping around haphazardly in a way that cannot be followed by a reader. This has the added benefit of assisting the organizational structure of my writing, as I can make paragraph breaks in between separate streams of thought.
Additionally, this method helps me in updating and improving my reasoning and thought. By interrogating each piece of my reasoning, from my evidence/premises all the way to my final conclusions, I can create an intricate picture of my ideas. I can also stress test the various components of my thought in more atomized ways. This helps me to assess where the weakest links are or where my ideas require further updating.
For understanding the thoughts and reasoning of others: I also use the stream metaphor to help me understand other peoples trains of thought. It is especially useful for figuring out where miscommunications or frustrations are occurring.
Oftentimes disagreements appear as being far downstream, for example regarding how one should implement a particular specific law. This can lead to writing off of other perspectives for being just too alien and incomprehensible. One may struggle to imagine how another person who is genuinely trying to reason about the subject could come up with the conclusions they arrive at.
When I encounter these struggles to communicate, they often revolve around upstream differences. When two people have highly divergent premises and evidence used in their thinking, they can oftentimes come to extremely different conclusions. For example, premises and conclusions about the proper role of government are often quite upstream in one’s thought process, and thus have massive impact when it comes to the sorts of conclusions one arrives at when discussing the quality of a specific government policy.
The process of drawing out upstream beliefs can be tedious and frustrating, especially when both parties believe their upstream beliefs to be obvious to anyone who thinks. This can lead to communication breakdowns, accusations and insults thrown, and a general failure to have any kind of constructive discourse.
Update about me: Sorry I haven’t posted in a while, I have been trying to deal with a lot of moving parts in my life. My current plan is to post something weekly, that kind of schedule would help many aspects of my page here.
As always, feel free to comment with feedback, thoughts, and constructive critiques.
I'll start with 'Thanks!' for offering your thoughts about the process of communication, and some factors that contribute to miscommunication and/or conflicting views.
I have some initial, half-baked reactions, not necessarily or entirely critical:
You state- "When two people have highly divergent premises and evidence used in their thinking, they can oftentimes come to extremely different conclusions."
My response- When two people begin with different premises and rely on differing types or standards of evidence, what appears to be discussion or argument between them is in reality two people talking past each other. Shared premises, and at least a provisional consensus about what constitutes 'legitimate' and 'relevant' evidence, are prerequisites for meaningful discussion can occur about a substantive matter, something that may be subject to disagreement. Accordingly, when there is apparent disagreement or miscommunication, we do well to inquire/determine if in fact we and our interlocutor are operating from different premises and evidence. (Side note- two people can hold different premises and rely on different standards of evidence, but still arrive at the same conclusion, which suggests that we need to be careful about assuming that shared views/conclusions on any particular subject implies shared basic premises.)
I think many of us, much of the time, don't reflect enough, and make explicit enough (to ourselves and others) what our premises are, and what we might take to be 'legitimate' and 'relevant' evidence. Revisiting our premises and evidence, subjecting them to scrutiny, can be unsettling, because given a second or third look, they aren't always as solid as we imagined.
I really like this entry! In think your metaphor about stand of thought is a useful one for organizing an argument!