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First principles thinking

Separate facts from assumptions and rebuild a testable solution from explicit constraints.

Separate observations from inherited assumptions, identify constraints, then rebuild a testable solution.

This worksheet organizes reasoning; it cannot verify facts or establish physical first principles for you. Up to 50 rows; 4,000 characters per section, 1,200 per table cell.

Open project

Project title

Problem to solve Describe the outcome without prescribing a solution.Known facts and evidence What is observed or measured? Cite your sources.Assumptions to challenge What are you accepting because it is customary?Fundamental constraints Include physical, time, legal and resource limits.Rebuilt solution What follows from the facts if you remove the assumptions?Smallest practical test Define a measurable test and what would change your mind.

Claim details
Claim	Fact / assumption / constraint	Evidence or source	How to verify	Remove
Claim 1	Fact / assumption / constraint 1	Evidence or source 1	How to verify 1

Your work stays in this tab. Nothing is saved automatically. Save a readable, unencrypted project file before closing. Downloads remain wherever you save them.

Processed on your device. Your files are never uploaded by Justility.

How privacy works

How it works

Open first principles thinking, enter your own project details or load the labeled example, then complete the prompts and review the worksheet. Review the results and download your project to continue later.

Supported formats

Editable JSON project up to 1 MB; plain-text report and CSV rows. Up to 50 rows, 4,000 characters per section and 1,200 per cell.

Good to know

Facts require evidence; the worksheet does not verify claims.

Worked example

Before

Packaging is costly; every product currently uses a separate box

After

An explicit shared-insert hypothesis and a controlled shipping test

Distinguish observed damage rates from the assumption that separate boxes are necessary.

First principles thinking: interpret the result

Separate facts from assumptions and rebuild a testable solution from explicit constraints. Facts require evidence; the worksheet does not verify claims. All project files are readable and unencrypted. Save and open them explicitly; there is no automatic browser persistence.

Five whys analysis

Troubleshooting

Does this worksheet discover fundamental truths?

No. It provides prompts to distinguish evidence, assumptions and constraints. You must verify claims and run the proposed test.

Common questions

Can I use first principles thinking offline?

Prepare this tool using Offline help while online. After preparation, it runs locally with fresh input. Browser cache eviction remains possible; keep project downloads separately.

Can I use this without an internet connection?

Yes, after you prepare this tool from Offline help and the browser retains its assets. Installation is optional. All processing dependencies are bundled locally.