diff --git a/lectures/_toc.yml b/lectures/_toc.yml
index a9e5b70e..7ba84da9 100644
--- a/lectures/_toc.yml
+++ b/lectures/_toc.yml
@@ -12,14 +12,14 @@ parts:
   - file: business_cycle
   - file: inflation_history
   - file: inequality
-- caption: Essential Tools
+- caption: Foundations
   numbered: true
   chapters:
-  - file: complex_and_trig
-  - file: linear_equations
-  - file: eigen_I
   - file: intro_supply_demand
-- caption: Linear Dynamics
+  - file: linear_equations
+  - file: complex_and_trig
+  - file: geom_series
+- caption: "Linear Dynamics: Finite Horizons"
   numbered: true
   chapters:
   - file: pv
@@ -27,7 +27,10 @@ parts:
   - file: equalizing_difference
   - file: cagan_ree
   - file: cagan_adaptive
-  - file: geom_series
+- caption: "Linear Dynamics: Infinite Horizons"
+  numbered: true
+  chapters:
+  - file: eigen_I
 - caption: Probability and Distributions
   numbered: true
   chapters: