Chemical rate theories have advanced by changing how a reaction is represented and which molecular quantities are calculated. Several advances also supplied controlled corrections to earlier theories. I connect this history, from Arrhenius to machine-learned potentials, to tests of the assumptions behind a calculated rate. Original sources clarify Marcelin's treatment of incomplete transmission and reactive-population depletion, and Christiansen's descriptions of orientation and collisional deactivation. Five numerical comparisons distinguish tests against experiment from tests using the same molecular model and from calibration. For hydrogen desorption from platinum, a published barrier adjustment improves absolute rate agreement but increases the spread of calculated-to-experimental ratios across temperatures; the source supplies no rate uncertainties. For triosephosphate isomerase, changing the prior on microscopic rates shifts the median inferred intermediate energy from 7.3 to 17.2 kJ/mol with the same inputs, likelihood, and bounds. This sensitivity calculation does not determine a preferred physical energy. I also examine how later molecular information can change the interpretation of older measurements. Hydrogen-oxygen chain branching provides a published reconciliation involving revised thermochemistry and dynamics. For pyrophosphate hydrolysis, conditional speciation identifies a potentially important complex containing two magnesium ions whose hydrolysis rate is not supplied by the recent calculations. Proposed tests use independent species populations, a later optical calibration of Criegee intermediates, and controlled temperature histories and local recession measurements in diamond dissolution.