Reasoning: Cherry Picking Lines of Evidence
How Judgment, Interpretation, and Bias Shape Our Understanding
Author’s Preface
Lines of evidence and cumulative argument are useful tools for structuring thought, but they do not lead to truth. They merely provide an organized way of thinking about uncertainty. The concept of evidence itself is problematic—there is always missing information, some evidence is outright false, and all evidence requires interpretation. Inference, too, is not algorithmic, and judgment is always flawed, biased, and dependent on worldview.
A person can cherry-pick lines of evidence as easily as they can cherry-pick any other information. The process depends on intellectual honesty and self-awareness—whether one is selectively emphasizing supporting data while ignoring or dismissing contradictory evidence. Even the idea of a "line of evidence" is flexible—it can be broken into sub-lines, aggregated into higher-order arguments, or reframed entirely. The structure of reasoning is subjective and exists within the constraints of individual perspective.
I have written separate essays on cherry-picking and on using lines of evidence in cumulative argument, which will be linked later. This essay focuses on the problems inherent in evidence, inference, and judgment, showing that structured reasoning is not a pathway to truth but rather a way to manage uncertainty.
Introduction
People often believe that lines of evidence and cumulative argument are tools for uncovering objective truth. In reality, they are organizational devices—ways to structure thought, categorize information, and make reasoning more coherent. They do not, however, ensure accuracy, reliability, or certainty.
The problem is fundamental: evidence is incomplete, inference is non-algorithmic, and judgment is biased. Even the structure of an argument is artificial and flexible—one can frame a "line of evidence" in many different ways, emphasizing certain elements, omitting others, or rearranging the hierarchy of reasoning.
This essay examines the inherent subjectivity of evidence, inference, and judgment, showing that reasoning, no matter how structured, does not escape bias, worldview, or interpretation. While lines of evidence help organize uncertainty, they do not resolve it.
The Problems with Evidence, Inference, and Judgment
The Problem of Evidence
It is always incomplete. No person has access to all the relevant evidence on any topic. Missing information is inevitable, and reasoning must proceed despite gaps in knowledge.
Some evidence is fraudulent or misleading. Distinguishing real from false, useful from irrelevant, or genuine from manipulated evidence is a constant challenge.
Evidence requires interpretation. There is no such thing as raw, self-explanatory evidence. All information is filtered through cognition, language, and conceptual framing.
Interpretation is not objective. The meaning of evidence depends on prior knowledge, experience, and underlying beliefs.
Cherry-picking is an ever-present risk. Selective use of evidence—highlighting supporting data while ignoring contradictory information—is a common cognitive tendency. Even when unintentional, confirmation bias leads people to favor evidence that aligns with their existing views.
The Problem of Inference
It is not algorithmic. Unlike a mathematical equation, inference does not operate according to strict rules that lead to guaranteed conclusions.
It depends on judgment, which is fallible. Inference is shaped by individual reasoning abilities, cognitive biases, and the limitations of human thought.
It is shaped by what is not known as much as by what is. Any inference involves assumptions, extrapolations, and interpretations of missing information.
Cherry-picking can affect inference. If someone selectively chooses evidence to fit a predetermined conclusion, their inference is not reasoned—it is rationalized. This is the difference between genuine reasoning and post hoc justification.
The Problem of Judgment and Interpretation
Bias is unavoidable. Every person interprets information through the lens of their existing worldview, experiences, and prior beliefs.
There are few incontestable facts. Many supposed "facts" are actually interpretations of observations rather than absolute truths.
The structure of reasoning is flexible. Even a "line of evidence" is an artificial construct:
One can break it down into smaller sub-lines or aggregate it into a broader argument.
Categorization is subjective. What counts as a distinct "line of evidence" is a matter of choice and perspective.
Intellectual honesty is necessary to mitigate cherry-picking. While cherry-picking cannot be eliminated entirely, it can be acknowledged and counterbalanced. This requires deliberately considering contrary evidence, alternative interpretations, and gaps in knowledge.
In the end, reasoning occurs within the constraints of one’s own worldview, and no person can fully escape this limitation. The best one can do is recognize bias, maintain intellectual honesty, and acknowledge the limitations of structured reasoning.
Summary: Organization Without Certainty
Lines of evidence and cumulative arguments do not establish truth—they are merely tools for organizing thought. Evidence is always incomplete and subject to interpretation, inference is non-algorithmic and based on judgment, and all reasoning is filtered through worldview and bias.
Cherry-picking is a central problem—selectively using evidence to fit a conclusion rather than forming a conclusion from all available evidence. Even structured arguments are susceptible to subtle forms of selection bias, leading to an illusion of rigor rather than genuine objectivity.
There is no escaping subjectivity. The best a person can do is engage in careful reasoning while remaining skeptical of their own conclusions. While structured reasoning helps manage complexity, it does not eliminate uncertainty, error, or bias. The pursuit of truth is constrained by human cognitive limitations, and any claim to certainty must be viewed with deep skepticism.
Ultimately, structured reasoning is a way of organizing uncertainty, not a pathway to truth.
Further Reading
I have written separate essays that explore:
Cherry-picking and the selective use of evidence
How to construct lines of evidence in cumulative arguments
These will be linked here when available.
Suggested Readings (APA Format)
On the Subjectivity of Evidence, Judgment, and Interpretation
Bloor, D. (1991). Knowledge and social imagery (2nd ed.). University of Chicago Press.
Feyerabend, P. (1993). Against method. Verso.
Goodman, N. (1978). Ways of worldmaking. Hackett Publishing.
On the Flexibility of Reasoning and the Limits of Objectivity
Hanson, N. R. (1958). Patterns of discovery: An inquiry into the conceptual foundations of thought. Cambridge University Press.
Lakatos, I. (1976). Proofs and refutations: The logic of mathematical discovery. Cambridge University Press.
Quine, W. V. O. (1969). Ontological relativity and other essays. Columbia University Press.
On Bias, Interpretation, and the Influence of Worldview
Bourdieu, P. (1990). The logic of practice. Stanford University Press.
Gadamer, H.-G. (2004). Truth and method (2nd ed.). Continuum.
Varela, F. J., Thompson, E., & Rosch, E. (1991). The embodied mind: Cognitive science and human experience. MIT Press.
This reading list provides philosophical and conceptual discussions on evidence, reasoning, and interpretation, avoiding the narrow focus of scientific methodology in favor of a broader epistemological perspective. These works explore the subjectivity of knowledge, the malleability of reasoning, and the inevitability of interpretation and bias—aligning with the themes of this essay.