diff --git a/submission_thesis/CH2_FMEA/copy.tex b/submission_thesis/CH2_FMEA/copy.tex
index 43484af..1f45bd4 100644
--- a/submission_thesis/CH2_FMEA/copy.tex
+++ b/submission_thesis/CH2_FMEA/copy.tex
@@ -743,7 +743,11 @@ will return most cost benefit.
 % \end{figure}
 Emphasis on determining criticality rather than the cost of system failures.
 Applies some Bayesian statistics (probabilities of component failures and those 
-thereby causing given system level failures)~\cite{bayesfrequentist}.
+thereby causing given system level failures).
+Applying Bayesian statistics to failure analysis, suffers the 
+problem that correlation does not imply causation~\cite{bayesfrequentist}. 
+However, correlation is evidence for causation, and maybe the only evidence to hand
+and this is the justification behind its use.
 A history of the usage and development of FMECA may be found in~\cite{FMECAresearch}.